Kamen Rider X vs Gatchan: who would win?

Gatchan favored — Favored (~65%)

Kamen Rider X · Kamen Rider · Skyrider, Super-1 & ZX

Tier

1-C

Attack Potency

Complex Multiverse Level

Speed

High Hypersonic, up to Ftl+

Durability

Multi-City Block Level, up to Complex Multiverse Level

Gatchan · Dragon Ball · Early Dr. Slump

Tier

1-C

Attack Potency

Complex Multiverse Level

Speed

Massively Ftl+

Durability

Multi-Solar System Level, up to Universe Level+

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