Ghidorah Rei vs Amon (Lord of the Mysteries): who would win?

Ghidorah Rei favored — Slight edge (~55%)

Ghidorah Rei · Godzilla · Base

Tier

LOW 7-C

Attack Potency

Small Town Level

Speed

Speed Of Light

Durability

Small Town Level

Amon (Lord of the Mysteries) · Lord of the Mysteries · Worm of Time

Tier

7-C, up to 1-A

Attack Potency

Town Level, up to Outerverse Level

Speed

Relativistic, up to Immeasurable

Durability

Athletic Human, up to Outerverse Level

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