Mugino Shizuri vs Joji Joestar: who would win?

Mugino Shizuri favored — Slight edge (~55%)

Mugino Shizuri · Toaru Majutsu no Index · Base

Tier

8-A, up to 7-C

Attack Potency

Multi-City Block Level+, up to Town Level

Speed

Athletic Human, up to High Hypersonic+

Durability

Multi-City Block Level+, up to Town Level

Joji Joestar · JoJo's Bizarre Adventure · Das Boot Ultimate

Tier

8-A

Attack Potency

Multi-City Block Level+

Speed

Hypersonic+, up to Massively Hypersonic

Durability

Wall Level, up to Large Building Level

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