Kamen Rider Kuuga vs Gilthunder: who would win?

Gilthunder favored — Slight edge (~55%)

Kamen Rider Kuuga · Kamen Rider · Amazing Mighty Form

Tier

6-C

Attack Potency

Island Level

Speed

Superhuman, up to Hypersonic

Durability

Island Level

Gilthunder · Nanatsu no Taizai · Post-Druid Training

Tier

6-C

Attack Potency

Island Level

Speed

Sub-Relativistic

Durability

Large Mountain Level

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