Magnetar is a boss added on May 24, 2020.
Design
Magnetar has a purple hexagon base which is based on a Semi-Swarm Crusher. Behind it has a Rocketeer cannon. It is smaller than Pulsar.
Technical
Magnetar has a lot of health, launches Rocketeer missiles, and has deadly body damage. It moves at a low speed.
Countering
Magnetar is intended to be a rammer, but in fact, it is not very deadly. It is not deadly mainly because of its low speed - Magnetar is one of the slowest bosses in the game. This is controversial with the fact its main weapon is body damage. However, do not underestimate the missiles, as the bullets they launch deal surprisingly decent damage.
This makes Magnetar easy boss to fight, but still, you must pay attention, especially missile bullets. The key is just staying in front of it while keeping some distance. When there are other players around, be especially careful. Magnetar has a lot of health, and you may be distracted. At this point, you may be vulnerable to players. If a player attacks you, retreat from the Magnetar as bullets may deal you some decent damage which can be crucial in PvP.