Optimus Prime (IDW 2005) vs Demon Anguirus: who would win?

Demon Anguirus favored — Slight edge (~55%)

Optimus Prime (IDW 2005) · Transformers · Base

Tier

HIGH 5-A, up to 1-A

Attack Potency

Brown Dwarf Level, up to Outerverse Level

Speed

Supersonic, up to Immeasurable

Durability

Brown Dwarf Level

Demon Anguirus · Godzilla · Base

Tier

HIGH 5-A

Attack Potency

Brown Dwarf Level+

Speed

Subsonic

Durability

Unknown

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