Flora vs Asa Mitaka: who would win?

Flora favored — Slight edge (~55%)

Flora · Berserk · Base

Tier
8-A
Attack Potency
Multi-City Block Level
Speed
Massively Hypersonic+
Durability
Multi-City Block Level

Asa Mitaka · Chainsaw Man · Post-Fear Boost

Tier
8-A, up to 6-C
Attack Potency
Multi-City Block Level, up to City Level
Speed
High Hypersonic, up to Relativistic
Durability
Multi-City Block Level

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