Chion vs Echidna (Re:Zero): who would win?

Chion favored — Slight edge (~55%)

Chion · Nanatsu no Taizai · Base

Tier

HIGH 7-A, up to 4-B

Attack Potency

Large Mountain Level, up to Solar System Level

Speed

Sub-Relativistic

Durability

Island Level

Echidna (Re:Zero) · Re:Zero kara Hajimeru Isekai Seikatsu · Base

Tier

6-C, up to 6-B

Attack Potency

Island Level, up to Country Level

Speed

Supersonic, up to Ftl

Durability

Human Level, up to Island Level

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