Frieren vs Aang: who would win?

Aang favored — Slight edge (~55%)

Frieren · Frieren: Beyond Journey's End · Base

Tier

LOW 7-C, up to 7-B

Attack Potency

Small Town Level, up to City Level

Speed

Hypersonic

Durability

Small Town Level

Aang · Avatar: The Last Airbender · Season 3

Tier

LOW 7-C, up to 5-C

Attack Potency

Small Town Level, up to Moon Level

Speed

Massively Hypersonic+

Durability

Small Town Level, up to Town Level

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