Wallflower Blush vs Three-Eyed Raven: who would win?

Wallflower Blush favored — Slight edge (~55%)

Wallflower Blush · My Little Pony · Base

Tier
10-B, up to 9-B
Attack Potency
Human Level, up to Wall Level+
Speed
Average Human
Durability
Human Level, up to Wall Level+

Three-Eyed Raven · Game of Thrones · Base

Tier
10-B
Attack Potency
Human Level
Speed
Immobile
Durability
Human Level

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