Doppelganger (Toaru) vs Vex: who would win?

Doppelganger (Toaru) favored — Slight edge (~55%)

Doppelganger (Toaru) · Toaru Majutsu no Index · Giant Body

Tier

HIGH 8-C

Attack Potency

Large Building Level

Speed

Superhuman

Durability

Large Building Level

Vex · Minecraft · Base

Tier

HIGH 8-C

Attack Potency

Large Building Level

Speed

Below Average Human, up to Subsonic

Durability

Small Building Level

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