Akira Otoishi portrait
Diamond is Unbreakable Infinity Boss

Akira Otoishi

Electric guitarist. Red Hot Chili Pepper plug-in invincibility.

5 Difficulties
5 Skills @ Hell
40,968 Crit boost @ Hell

Difficulty scaling

Engine-side ATK is a sentinel — damage flows through crit boost. Each tier ratchets crit until Hell locks in a ×2.5 multiplier on every swing.

Tier 1

Normal

Mon #53410011
ATK (sentinel) 999,999,999
Crit Boost 5,613
Crit Dmg 1,871
Hit Rate 20,000
Dmg Reduction 12,000
5 skill IDs 4100100, 4100111, 4100121, 4100131, 4100141
Tier 2

Advanced

Mon #53410012
ATK (sentinel) 999,999,999
Crit Boost 15,109
Crit Dmg 8,756
Hit Rate 20,000
Dmg Reduction 12,000
5 skill IDs 4100100, 4100112, 4100122, 4100132, 4100142
Tier 3

Difficult

Mon #53410013
ATK (sentinel) 999,999,999
Crit Boost 15,109
Crit Dmg 17,628
Hit Rate 20,000
Dmg Reduction 12,000
5 skill IDs 4100100, 4100113, 4100123, 4100133, 4100143
Tier 4

Nightmare

Mon #53410014
ATK (sentinel) 999,999,999
Crit Boost 26,264
Crit Dmg 26,264
Hit Rate 20,000
Dmg Reduction 12,000
5 skill IDs 4100100, 4100114, 4100124, 4100134, 4100144
Tier 5

Hell

Mon #53410015
ATK (sentinel) 999,999,999
Crit Boost 40,968
Crit Dmg 34,140
Hit Rate 20,000
Dmg Reduction 12,000
5 skill IDs 4100100, 4100115, 4100125, 4100135, 4100145

Lore & design notes

Akira's gimmick is plug-in invincibility — his kit lets him enter an unkillable state by drawing electricity. The game encodes that with 1.2× dmg_reduction (12000) and 1.2× secondary defense (12000) at every tier, which is unique among Infinity bosses. He hits harder than Tarukus or Wamuu at any difficulty, but the trade-off is that he is a pure single-phase fight — no transformations.

Counter team

Diamond is Unbreakable squad

Lineup

  • Josuke Higashikata — Crazy Diamond burst + sustain
  • Okuyasu Nijimura — shred / The Hand spatial damage
  • Koichi Hirose — Echoes 3 Freeze for crowd control

Why it works

Part 4 squad bonus stacks with Josuke's innate sustain. Echoes 3 Freeze is the cleanest answer to Akira's plug-in windows because it pauses his action queue entirely.

Watch out

Akira's dmg_reduction is permanent, not conditional — your raw DPS calculations need to bake in the 1.2× effective HP multiplier or you will under-budget your burst window.

Identity

Name Akira Otoishi
Part Diamond is Unbreakable
Boss type 4
Infinity Boss Yes
Monster template 53,410,011
Name ID 340,140,001
Difficulties 5