Here's some more weapons from ULTRAKILL:
Feedbacker Arm

This is a skill item with a cool down of 1-2 seconds. A successful parry resets the cooldown. A punch is inflicted instead if an enemy is in front of you.
Can only parry in front of you similar to parry shield or shields in general. Parrying an enemy projectile increases the damage of the said projectile, parrying a melee attack enrages the parried enemy and relentlessly chase you, but they would inflict more damage from you similar to the taunt skill.
Knuckleblaster

A weapon item that only occupies one slot.
The first attack is always a severe critical hit, the second attack would follow after a successful strike on the first one, this time everything around you will be repelled and even take fall or wall damage.