Overview
This endgame build runs Impending Doom as its chaos damage engine, but swaps a traditional caster ascendancy for the Gemling Legionnaire. The Gemling’s gem-focused nodes push key skill gems toward level 40 and stack large amounts of gem quality through Advanced Thaumaturgy, which is where most of the scaling comes from.
The result is a screen of self-propagating chaos explosions: Doom Blast detonations chain through packs while the character keeps casting. A 0-mana Despair curse setup frees up resources, and trigger efficiency is boosted by Trickster’s Shard. Mystic Avalanche extends coverage across the screen for map clear, while a dedicated “Chaosblast” weapon built around Blackflame Covenant handles pinnacle bosses.
The creator pitches it as a T16 mapper that also melts pinnacle bosses, with a dedicated bossing rotation covered separately from the mapping setup.
Pros & Cons
Pros
- Huge gem levels and quality from Gemling Legionnaire scale every core skill
- Autonomous chain explosions give strong, low-effort map clear
- Dedicated boss rotation and weapon swap for pinnacle content
- Despair curse runs at zero mana cost
Cons
- Endgame-oriented: relies on specific uniques and a crafted wand, focus and amulet
- Multiple interacting mechanics (Doom Blast cooldown, cast speed, spirit budgeting) make it complex to tune
- Not a fresh-league starter
Key Skills
- Impending Doom / Doom Blast — core chaos damage that detonates and chains through packs
- Despair — curse, run at 0 mana
- Mystic Avalanche — screen-wide coverage for mapping
- Chaosblast (Blackflame Covenant setup) — single-target boss damage
Gear & Anointments
Key pieces named in the guide include Doedre’s Undoing, Trickster’s Shard, Mystic Avalanche and Blackflame Covenant, alongside a crafted wand, focus and amulet (a crafting guide is promised by the creator). Thaumaturgical Dynamism and Advanced Thaumaturgy are central to the gem scaling. Exact stat priorities and socketables are to be confirmed against the source video and the linked build planner.
Endgame Notes
The guide covers a separate bossing rotation and the interaction between cast speed and the Doom Blast cooldown, which matters most for pinnacle encounters. Spirit is tight, so the spirit cost breakdown in the video is worth following closely.
Credits & Source
Build credited to ichigo. See the source video for full gameplay footage and commentary: PoE2 0.5 | The Chaos King Full Impending Doom Endgame Showcase Guide.