Gil-galad vs Izraf: who would win?

Izraf favored — Slight edge (~55%)

Gil-galad · Lord of the Rings · Base

Tier

HIGH 7-A, up to HIGH 3-A

Attack Potency

Large Mountain Level, up to High Universe Level

Speed

Supersonic+, up to Massively Ftl+

Durability

Large Mountain Level, up to High Universe Level

Izraf · Nanatsu no Taizai · Base

Tier

HIGH 7-A, up to 6-C

Attack Potency

Large Mountain Level, up to Island Level

Speed

Sub-Relativistic+

Durability

Large Mountain Level, up to Island Level

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