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Keelan Build Guide – Corrosion, Dash, and Hit-and-Run Burst

A Keelan build for The First Descendant: stack Acidic Decay, chain Onslaught dashes, and turn raw mobility into massive single-target damage.

6 min read

Keelan is a hit-and-run menace. He paints enemies with Acidic Decay, then deletes them with rapid dashes and explosions. If you like aggressive, mobile play that still rewards skill timing, he is one of the most satisfying Descendants to main.

The Corrosion Loop

  • Void Corrosion fires a projectile that applies Acidic Decay; hitting an already-decayed target deals bonus damage.
  • Onslaught is the star: dash through enemies, spread Acidic Decay, and detonate at the end. Pierce two or three targets per dash to refund cooldown.
  • Septic Gust converts Acidic Decay into Blood Rot, a delayed explosion – great for grouped mobs.
  • Tremor consumes your decay stacks for burst damage, or banks Onslaught stacks if nothing is decayed.
  • Passive Erosion builds Acidic Infusion from repeated skill use, granting Skill Power and Movement Speed. Keep dashing and it snowballs.

The Must-Have Transcendent

Mobile Strike replaces Septic Gust with Hunting Time, granting Adventurer’s Spirit so Onslaught stacks stop decaying for a window. That is what lets you chain dashes almost indefinitely. For pure bossing, Focus on Prey reshapes Void Corrosion into a single-target monster instead.

Modules

Stack Toxic skill power and cooldown: Focus on Toxic, MP Conversion, Nimble Fingers, Singular Amplification, and Stim Accelerant for HP. The goal is to keep Onslaught ready and keep moving.

Reactor and Weapons

A Toxic reactor is non-negotiable. Pair it with a weapon that can punch weak points during your dash windows – anything stable works, since most of Keelan’s damage is skill-based.

Playstyle

Open with Void Corrosion to seed decay, then Onslaught through packs. Never stand still; his value is in repositioning while deleting. He is excellent in Void Intercept and the new mega dungeons. If you want to compare him against other aggressive options, our tfd-tier-list has the rankings, and tfd-modding-guide covers catalysts. Just unlocking him? See tfd-unlock-descendants-guide for the Void Vessel farm.

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