Ariu Mikaboshi vs Kirika Kure: who would win?

Kirika Kure favored — Slight edge (~55%)

Ariu Mikaboshi · Kagurabachi · Base

Tier
7-B
Attack Potency
City Level
Speed
Massively Hypersonic, up to Sub-Relativistic
Durability
City Block Level, up to City Level

Kirika Kure · Puella Magi Verse · Magical Girl Form

Tier
7-B
Attack Potency
City Level
Speed
Massively Hypersonic
Durability
Small Town Level

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