Kamen Rider Saikou vs Carla Radames: who would win?

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

Kamen Rider Saikou · Kamen Rider · Base

Tier

9-B, up to 1-C

Attack Potency

Wall Level, up to Complex Multiverse Level

Speed

Massively Hypersonic, up to Massively Ftl+

Durability

Wall Level, up to Complex Multiverse Level

Carla Radames · Resident Evil · Base

Tier

9-B, up to 9-A

Attack Potency

Wall Level, up to Small Building Level

Speed

Superhuman, up to Supersonic

Durability

Wall Level+, up to Small Building Level

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