Sheath

The Sheath is a Tier 4 that upgrades from the Flank Machine and the Submachine at Level 45.

Design
The Sheath appears to be just a Flank Submachine, with 3 thin barrels on each of its 3 barrels

Technical
The Sheath fires small, Pelleter-like bullets on each of its barrels.

Upgrades
The Sheath upgrades from the and the  at level 60:

The Sheath can upgrade into the following:

As the Sheath

 * It's best to just press the keys C+E.
 * Stay far away from bullet spammers, especially the Twisted Hybrid. Their bullets will easily outpenetrate your bullets.
 * Say away from Sniper-branch tanks.
 * The only thing you can do is take advantage of Tanks such as the Redistributor.

Against the Sheath

 * Just don't be in the line of bullets and you're fine.