Gokusai Kaibi vs Children of the Forest: who would win?

Gokusai Kaibi favored — Slight edge (~55%)

Gokusai Kaibi · Toaru Majutsu no Index · Base

Tier

9-C, up to 9-B

Attack Potency

Street Level, up to Wall Level

Speed

Average Human

Durability

Human Level

Children of the Forest · Game of Thrones · Base

Tier

10-B, up to 8-C

Attack Potency

Human Level, up to Building Level

Speed

Peak Human, up to Subsonic

Durability

Human Level

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