Exploding Bullet

Every round pops into a small blast when it lands, on an enemy or on terrain. That turns any gun into a light crowd clearer and gives you a way to hurt segmented targets where a single round would only touch one part. The knockback is heavy for a bullet, which helps in a corridor and hurts when you are trying to hold something in place.

Landing a hit puts a short immunity window on the target. The bullet itself does not care, since it stops on contact, but its own explosion can arrive inside that window and do nothing at all. It also swallows hits from anything piercing you fire alongside it, so running these with a weapon like the Onyx Blaster wastes part of both.

Shotguns are the obvious match. A wide spread turns a wave of enemies into overlapping blasts, and the Tactical Shotgun in particular deletes groups with these loaded. Against a single boss, Crystal Bullets usually win. Materials come straight off town vendors, so you never farm for them, and they no longer hurt you when you fire into a wall at your feet.