Thanos (Marvel Cinematic Universe) vs Adam (Hazbin Hotel): who would win?

Too close to call

Thanos (Marvel Cinematic Universe) · Marvel · Base

Tier
LOW 5-B, up to LOW 2-C
Attack Potency
Small Planet Level, up to Universe Level+
Speed
Subsonic, up to Massively Hypersonic+
Durability
Small Planet Level, up to Planet Level

Adam (Hazbin Hotel) · Hazbin Hotel · Base

Tier
LOW 5-B, up to 5-B
Attack Potency
Small Planet Level, up to Planet Level+
Speed
Supersonic, up to Supersonic+
Durability
Small Planet Level, up to Planet Level+

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