Onslaughter is the Action Skill of Amon's Calamity skill tree in Borderlands 4.

Effects

Grants the Molten Slam Forgeskill. Amon overloads his Forgefist, gaining constant Shield Regeneration, Bonus Incendiary Damage with Guns, and increased Movement Speed.

• Shield Regeneration: +15%
• Incendiary damage: +25%
• Movement Speed: +30%

Press Action Skill or Melee to Rocket Punch, Dashing to target enemy, dealing Incendiary Melee Attack Damage in a short-ranged Cone, and causing Stagger. Bosses cannot be Staggered, and Badasses have a chance to be Staggered.

Change History

• The October 2nd, 2025 patch increased shield regeneration from 10% per second to 15% and Rocket Punch damage by 78%. Molten Slam's damage was also increased by 50%, and its cooldown to reduced from 80 seconds to 60 seconds.
• The October 23rd, 2025 patch fixed Rocket Punch's frequency to be more consistent in multiplayer.
• The May 28, 2026 patch fixed Rocket Punch to correctly boost Shield Regeneration Rate when paired with Impetus.