Kamen Rider Knuckle vs Ashiya Douman: who would win?

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

Kamen Rider Knuckle · Kamen Rider · Base Forms

Tier

1-C

Attack Potency

Complex Multiverse Level

Speed

Massively Ftl+

Durability

Complex Multiverse Level

Ashiya Douman · Nasuverse · Rakshasa King

Tier

1-C

Attack Potency

Complex Multiverse Level

Speed

Ftl, up to Immeasurable

Durability

Complex Multiverse Level

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