Irmo vs Kamen Rider Zangetsu: who would win?

Kamen Rider Zangetsu favored — Slight edge (~55%)

Irmo · Lord of the Rings · Prior to entering Eä

Tier

1-A, up to HIGH 1-A

Attack Potency

Outerverse Level, up to High Outerverse Level

Speed

Massively Ftl+

Durability

Outerverse Level, up to High Outerverse Level

Kamen Rider Zangetsu · Kamen Rider · Saver System

Tier

1-A

Attack Potency

Outerverse Level

Speed

Immeasurable

Durability

Outerverse Level

A heuristic estimate from normalized VS Battles Wiki stats: tier, attack potency, speed and durability.