The Catabolyst really benefits from projectile speed rivens to decrease it's damage fall-off, and has 4 riven dots
So this is a heat inherit build which is super strong on most held weapons, even better with secondaries due to the cascadia flare arcane which will grants us free [Hornet Strike] but doubled... It stacks very easily with this weapon
[Primed Fulmination] benefits from both primary fire and reload, giving it extra range and group killing... but it can be changed to lethal torrent for faster heat inherit
Ruinous extension is good, however... Ammo pick-up is 20, so (primed) [Pistol Ammo Mutation] can keep this weapon going
The grenade is so satisfying to use with [Gyre]'s Coil Horizon, i'll tell you that