Kamen Rider Specter vs Alfonse: who would win?

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

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

Tier

1-C

Attack Potency

Complex Multiverse Level

Speed

Ftl

Durability

Complex Multiverse Level

Alfonse · Fire Emblem · Book I

Tier

1-C

Attack Potency

Complex Multiverse Level

Speed

Superhuman, up to Massively Hypersonic+

Durability

Complex Multiverse Level

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