Riku vs Kamen Rider Specter: who would win?

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

Riku · Kingdom Hearts · KH3D

Tier

1-C

Attack Potency

Complex Multiverse Level

Speed

Athletic Human, up to Infinite

Durability

Complex Multiverse Level

Kamen Rider Specter · Kamen Rider · Beginning of Series (1-12)

Tier

1-C

Attack Potency

Complex Multiverse Level

Speed

Ftl

Durability

Complex Multiverse Level

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