History of Breakthrough (perk)

Overview

Breakthrough is the trait on Bastion, an Exotic Fusion Rifle. It makes the weapon fire staggering projectiles that are strong against Unstoppable Champions. A single hit can stagger a champion that would otherwise keep rushing you, so it is a useful answer for those enemies.

Destinypedia lists Breakthrough among the selectable traits and gives the intrinsic as Saint's Fists. A 2022 Sportskeeda article describes the anti-Champion effect as intrinsic. The newer sources are more likely to be correct, but check the in-game perk pool.