Archaon vs Mind Flayer: who would win?

Mind Flayer favored — Slight edge (~55%)

Archaon · Warhammer Fantasy · Archaon

Tier

HIGH 4-C, up to LOW 2-C

Attack Potency

Large Star Level, up to Universe Level+

Speed

Massively Hypersonic, up to Speed Of Light

Durability

Large Star Level

Mind Flayer · Dungeons & Dragons · Peak Technology

Tier

HIGH 4-C, up to 2-A

Attack Potency

Large Star Level, up to Multiverse Level+

Speed

Ftl

Durability

Large Star Level

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