Archaon vs Kamen Rider W: who would win?

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

Archaon · Warhammer Fantasy · Archaon

Tier

HIGH 4-C, up to LOW 2-C

Attack Potency

Large Star Level, up to Universe Level+

Speed

Massively Hypersonic, up to Speed Of Light

Durability

Large Star Level

Kamen Rider W · Kamen Rider · Post-Futo Tantei

Tier

HIGH 4-C, up to 4-B

Attack Potency

Large Star Level, up to Solar System Level

Speed

Ftl

Durability

Large Star Level, up to Solar System Level

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