MK-X

The MK-X (MarK-X) series of bosses based on the Square. This is the first X-K-X boss, surpassing even EK-X and TK-X. Originally, it was named MK1 and was added on October 7, 2018. MK-2 and MK-3 tiers were added the same day. MK-4 was added later on the same day, four hours later, and the tier system was renamed to MK-X one hour later. MK-5 was added on July 15, 2018, and was heavily nerfed the same day. Originally, it had six minions of both types, but now it has only three minions of both types.

MK-X series is mainly based on swarm drones and all have a square yellow base. MK-1 is even weaker than EK-1, but all higher tiers are more based on swarm drones. Minions are also a pretty important part of the MK-X boss. MK-5 is based on bullets, swarm drones, and minions. MK-2, MK-3, and MK-4 are more based on drones/swarm drones. MK-4 is mostly based on swarm drones, as they are very strong. Also, MK-2 has a Hybrid auto-turret, which is obtained only by a few other bosses like C.L.O.C.K. or Destroyer.

MK-X cannot currently spawn in the game under any circumstances and is on the TESTBED bosses branch. The two highest tiers are blatantly OP, and MK-5 can cause some lag to the server because of its bullets, size, and minions.

Tiers
MK-1=

Design
MK-1 has a yellow square base with two turrets in front supported by a trapezoidal base and an auto-Assassin turret on top.

Technical
MK-1 has low health and speed. Its auto-turret has a low rate of fire and bullet health, but decent damage. Its bullets have a decent penetration and high damage and are fired at a fast rate.

Countering
MK-1 may seem easy to fight, but still, you must be careful. As a bullet spammer, you will likely face no problems in killing MK-1, as you have more firepower. Still, the boss may out-gun you if you will not dodge, so you should also move in a left-right pattern to make sure MK-1 will miss more. As a tank with a long range and low rate of fire, try to keep a longer distance and wait until the boss will be distracted.

As a drone user, you have a slightly different strategy. As a drone user, wait until you have a maximum number of drones, and then charge them at MK-1 when it will be distracted. As a minion user, you can use either strategy. Be wary of other players around, though. MK-1 can easily eliminate you with its high damage if another player attacks you. Eliminate the player first, then come back to killing MK-1. Do not be afraid to ram into MK-1 if it is low on health, but never try to ram it if it is locked on you.
 * -|MK-2=

Design
MK-2 has a yellow square base with a large Nailgun turret in front, and two Sounder barrels on each side. On top, it has an auto-Hybrid turret and two Assassin auto-turrets behind it.

Technical
MK-2 has a medium health and low speed. Its hybrid drones will only lock on the player if he will come close, and have low range. However, these drones are surprisingly strong, have high health and damage. Swarm drones have low health and speed, but high damage. Assassin turrets have a high bullet speed and damage, but low penetration. Bullets of the front turret have medium speed, but no spread and high penetration along with high damage.

Countering
MK-2 has pretty high firepower which can hold off many tanks, and its swarm drones will be easily able to kill you. It is challenging to counter MK-2, as you will not usually be able to kill it before it will kill you. Whenever you this boss, it is advised to run as usually you will not stand many chances against it. If you are skilled, however, you may consider using these strategies.

Firstly, the Engineer branch is pretty effective if you are skilled enough, as bullets from pillboxes will eliminate swarm drones. You should upgrade your movement speed a lot so you can dodge all of the bullets, as well as block health. Some bullets will be dealing low damage to the boss, and you will eventually kill it. Splitter can also be very effective against MK-2, as you can dodge and eliminate swarm drones, as well as deal very high damage. Fighting in teams is by far the most efficient way of killing MK-2, as one player will distract the boss, while others will be killing it. Dodging in a left-right pattern, in either case, is important and vital to defeating the boss.
 * -|MK-3=

Design
MK-3 has a yellow square base with a large Artillery auto-turret on top, a Trapper auto-turret behind it, and two Director auto-turrets to the sides of the artillery turret. In front of its base, MK-3 has two Minigun turrets near edges and two Streamliner turrets between them. At the back of its base, MK-3 has two Underseer barrels.

Technical
MK-3 has a low speed and normal health, and very high firepower. Streamliner and minigun barrels have decent bullet speed and damage, as well as high penetration. MK-3's artillery turret has a high rate of fire, damage, and penetration. Drones of MK-3 have decent speed, high health, penetration, and damage. MK-3 also spawns medium-strength underseer drones, but they are spawned at a very low rate and do not help the boss much. Traps of MK-3 have high speed and damage, but low health. MK-3 also spawns four Square Twins, which add up a lot of firepowers, swarm drones and are the main strength of the boss.

Countering
MK-3 has very high firepower and can easily penetrate any normal tank. Furthermore, MK-3 has very strong drones that can also easily eliminate any tank and four minions that have more firepower than this boss and are respawned immediately after dying. Small groups of players will not stand chance against MK-3, so if you ever see this boss, you have only one option - 'RUN. 'If Square Twin is chasing you, visit its respective section to understand how to handle it.

Killing MK-3 is very hard since it will require your team to be very coordinated. Drones and swarm drones are the largest problems since they will likely eliminate most tanks before the boss will be defeated. Firstly, you should get at least four Hexa Builders in the same team, which should keep themselves close. They will eliminate all minions, drones, providing a much-needed diversion. Secondly, you should get two tanks with a lower danger value, ideally Twinceptionists, which will deal damage to the boss. At least two such tanks are needed, and they should keep a distance from the boss. If everything is done right, MK-3 will fall as it will not be able to defend itself.
 * -|MK-4=

Design
MK-4 has a yellow square base with a unique auto-turret on top. This auto-turret has a yellow base with four slanted bases around it. In front of each such slanted base, MK-4 has a smaller Quintuplet turret. In corners of its base, MK-4 has four Sounder auto-turrets, and four Frigate auto-turrets between them. On corners of its outside base, MK-4 has four Barricade auto-turrets. On each side of its outside base, MK-4 has two Spawners and a Constructor turret between them.

Technical
MK-4 has a low movement speed and high health, higher than most normal bosses. Its quintuplet bullets are strong, have high health and penetration, decent speed, and cover a wide area. Its constructor turrets launch very strong blocks at a low rate, which have high health and lethal damage. Its traps are fired at a fast rate, but have medium-range and health, but still nearly lethal damage. All swarm drones have high speed and damage, as well as decent health for a swarm drone. Frigate swarm drones have more health and damage, but lower movement speed. MK-4 also spawns 8 minions, which have a yellow color and a single Basic turret in front. These minions have a high speed and high combined DPS, but low health. Four such minions are respawned every 2 seconds. MK-4 also spawns three Auto Squares, which respawn immediately after dying.

Countering
Killing MK-4 is a major challenge, far harder than killing MK-3 or any other normal boss. MK-4 can perish any tank at most ranges with help of its minions in a matter of seconds. Due to the heavily increased amount of swarm drones compared to MK-3 and far more dangerous minions of both types, it will be incredibly difficult to defeat this boss. If you ever see MK-4 or any of its minions, you have only one option - 'RUN. 'If basic minions are chasing you, eliminate them one by one. If Auto Square is chasing you, refer to its respective section to understand how to handle it.

It will be very tough to defeat MK-4, as it has high health and you will not be able to come close enough to kill it. Combatting it will require your team to be very coordinated, using right tanks and strategy. Firstly, you should get a Jump Smasher to distract all the minions from the boss itself, or otherwise you stand little chances. This player should not lure minions too far away from the boss, so they wil always be locked on the player. While minions are distracted, MK-4 will be more vulnerable to account. Swarm drones are still a major concern, so getting two Hexa Blasters in the same team will be helpful to eliminate them and survive onslaught of the boss. Finally, you will need a tank with high penetration, like Redistributor, and at least two tanks with high RoF, like Machceptionists, to eliminate traps and bullets of the boss. Do not hit through the blocks, as you will waste too much time trying to penetrate them. If pulled off correctly, you will be able to kill MK-4 effectively. VPN just does not stand a chance since it will not be able to penetrate its minions which will circle around the boss.
 * -|MK-5=

Design
MK-5 has a large yellow square base with a unique auto-turret on top. This auto turret looks like Octo Machine, but diagonal turrets are shorter and of a basic type, and also have two more Basic barrels, which can be barely seen. Around the barrels, there are eight Beehive auto-turrets and four Waveform auto-turrets. Beehive auto-turrets are in horizontal and vertical directions, two on each side, while waveform auto-turrets are in diagonal directions. In the center of each side of its base, MK-5 has a large unique auto-turrets, which has an Assassin barrel in the middle, and two shorter barrels that have a long slanted base but short barrels on sides. To the sides of each such turret, MK-5 has two Predator auto-turrets and a Spawner in each corner of the base.

Technical
MK-5 has a very low movement speed and high health and slowly spins. The main turret of MK-5 is very strong, has a high rate of fire, penetration, and bullet damage, as well as covering a wide area. Its beehive swarm drones are surprisingly strong compared to its tank counterpart, have high speed, damage, and decent health. Its waveform swarm drones have a very high speed and damage. MK-5's unique turrets on sides are also very strong, as they shoot powerful bullets with very high health and lethal damage. Its predator bullets are of medium strength, have decent damage and bullet speed. MK-5 also spawns six minions, three Mega Auto Squares, and three Square Assassin. These minions respawn immediately after dying.

Countering
MK-5 has incredibly high DPS, high health, and very deadly minions. It can easily perish any tank, even Coiffure, in a matter of seconds. Furthermore, MK-5 has very strong swarm drones which also can eliminate any player. Minions respawn immediately after death and are very fast and hard to deal with. As such, if you see MK-5's minions or MK-5 itself, you have only one option - run.

But even running away from this boss is a major problem. In general, if swarm drones locked on you, you are screwed. Try to avoid bullets of the boss while running away as much as possible, moving in a left-right pattern. It will require a bit of luck, but if you manage to do it only minions will lock on you. Mega Auto Squares are the most dangerous minions while running away. Usually, you should try to find an obstacle and break up the maximum distance, or otherwise, you stand little chances unless you are faster than minions. If sniper or twin minions are chasing you, eliminate them first, or else you will take massive damage.

Killing MK-5 is a major challenge, far harder than killing MK-4 or most bosses. Firstly, you will likely die if you do not distract Mega Auto Squares from the boss, as they have enough health and penetration to kill you. Distracting Mega Auto Squares is the first concern when fighting with MK-5, and you will need a Shooting Star for this. This player should just guide minions away from the boss, but not too far away so they will still be locked on distracting players. Secondly, you should distract the Square Assassins from the boss, ideally by luring them. These minions are faster than the boss itself, so getting a Coiffure which will keep a long distance and slowly lure minions is effective. After the distracting players died and minions are far away, MK-5 will be more vulnerable. Using at least seven Hexa Builders in the same team is the most effective way to defend yourself from the boss, and then keep up on attacking it. You will also need at least two Redistributors, and ideally a Surge with some Twinceptionists to deal damage to the boss. The more DPS you have, the better, as MK-5 will fall faster and you will be able to achieve victory.

Minions
Square Twin=

Design
Square Twin has a yellow square base with four Twin auto-turrets on top and two Frigate barrels on sides.

Technical
Square Twin has somewhat low movement speed and mediocre firepower. Its bullets are fired at a fast rate but have medium damage and penetration. Swarm drones it spawns are strong, have medium speed but high damage, and decent health.

Countering
Square Twin will respawn immediately after you kill it, so there is no sense in fighting it. Furthermore, it can be dangerous and comes in a number of four. As such, whenever you see a Square Twin it is advised to run. Try to dodge slow swarm drones, while shooting them to avoid taking damage. If you are forced to defend against a single such minion, you should charge at it. It has low health, so you will likely kill it before it will kill you. Never attack multiple Square Twins, as they will shred you before your tank will kill either of them. Also, never stay at a long range as that's where the swarm drones of the Square Twin are strongest. Smasher branch is not suggested, as you will take nearly lethal damage and likely die if Square Twin shoots at you.

In order to understand how to handle this minion if there is also a living MK-3 around it, refer to its respective boss section.
 * -|Auto Square=

Design
Auto Square has a unique auto-turret on top, which is called Weird Assassin, has an Assassin turret as a base, and two more very short stacked turrets in front of it. In front, Auto Square has a Ranger turret, machine thruster at back, and two auto-turrets on each side.

Technical
Auto Square has a decent movement speed and low health, as well as decent penetration. Its ranger turret and weird assassin turrets have a strong penetration but mediocre rate of fire. Auto-turrets have medium bullet health and penetration, but a far higher rate of fire. Auto Square's thruster bullets deal little to no damage, and only propel Auto Square forward.

Countering
Auto Square will respawn immediately after you kill it, so there is no sense in fighting it. Furthermore, it can be dangerous and comes in a number of three and has a high speed. It is advised to run away as fast as possible if there are two or more Auto Squares, but you can handle a single one. In order to do so, you should use a tank with high-to-medium movement speed, and high DPS. You should move in a left-right pattern while retreating to trick Auto Square into missing more. In the meanwhile, you should deal heavy damage to the boss, and it should die fast. Be vary of weird assassin turret, as it has high damage and you must avoid those bullets.

In order to understand how to handle this minion if there is also a living MK-4 around it, refer to its respective boss section.
 * -|Mega Auto Square=

Design
Mega Auto Square has a yellow square base with a very large Triple auto-turret on top and a large Wanderer turret in front. On sides of its base, Mega Auto Square has four Streamliner auto-turrets, two on each side. At the back, Mega Auto Square has two Machine Gun thrusters and a Blaster thruster between them.

Technical
Mega Auto Square has a high movement speed and somewhat low health. Its wanderer bullets are very strong, have very high damage and penetration. Triple bullets are also very strong, but they have lower bullet speed and damage. Streamliner turrets have a high bullet speed and decent penetration, as well as a very high rate of fire. Streamliner bullets by themselves are pretty weak but are very strong combined. Thruster bullets deal little to no damage and are only used to boost Mega Auto Square forward.

Countering
Mega Auto Square will respawn immediately after you kill it, so there is no sense in fighting it. Furthermore, it can be very dangerous because of high firepower and speed and comes in a number of three. Mega Auto Square is faster than most non-Propeller branch tanks, which may prove a problem in killing it. Firstly, as soon as you see Mega Auto Square, you should run to the closest rock as fast as possible, or else you have little chances. If you managed to get to the opposite side of the rock and Mega Auto Square is still locked on you, you have two options. The first option is viable for trappers, drones, and minion users - it is to kill Mega Auto Square. However, be vary as you will need to find multiple rocks in a line to not get hit by bullets. The second option is to run away from Mega Auto Square as fast as possible, in order to get out of its field of view.

If there is also a living MK-5 around it, refer to its respective boss section to understand how to handle this minion.
 * -|Square Assassin=

Design
Square Assassin has a yellow square base, with a unique turret on top. This unique turret looks like a Ranger auto-turret on an extra slanted base. Around this unique turrets, there are nine more Assassin auto-turrets. On corners of its base, Square Assassin has four spawners that spawn Twin minions. On sides of its base, Square Assassin has two Mega Trapper turrets, and a Spawner turret between them, which spawns Sniper minions.

Technical
Square Assassin has a low movement speed and medium health and always spins. Its unique turret acts as a stronger version of the ranger, has a high bullet speed but mediocre penetration. Its nine assassin turrets add up a lot of firepower to the boss, as they have nearly the same stats, slightly lower bullet speed, and damage. Mega traps have low range, but allow Square Assassin to create a defensive barrier as they have high health. Square Assassin also spawns eight minions, four twins, and four snipers, which makes this mini-boss very dangerous. They have low health but high speed and decent DPS and are respawned 2 seconds after dying.

Countering
Square Assassin will respawn immediately after you kill it, so fighting it is useless. Furthermore, it is hard to kill Square Assassin because of its traps, and it has decent firepower. What's worse each Square Assassin spawns eight strong minions and Square Assassins come in a number of three. Considering this, it is advised to flee as soon as you see Square Assassin. However, some tanks can kill it in solo with needed skills. One of such tanks is Splitter, as it has more DPS and can run away from minions for some time. You must firstly charge all your minions into the mini-boss, then eliminate Square Assassin's minions, and repeat the procedure. However, this requires skill and you will die if another player attacks you. As such, running away from Square Assassin is the best option.

If there is also a living MK-5 around it, refer to its respective boss section in order to understand how to handle this minion.

Trivia

 * MK-X is the very first X-K-X boss that officially got a tiering system.
 * MK-X is the only boss which does not mean X-King-X.
 * MK-5 originally had six minions of each type, but it was decided to be too overpowered. Later, the minion count was nerfed from six to three.
 * Second to last tiers of MK-X share a consistency of using swarm drones.
 * MK-2 is one of few bosses which has a hybrid auto-turret.
 * One of MK-4's minions Auto Square has a unique Auto Turret named Weird Assasin. However, there are two different turrets with the same name (Weird Assassin) for both Auto Square and Square Assassin.