Maidono Hoshimi vs Mason cannon: who would win?

Mason cannon favored — Slight edge (~55%)

Maidono Hoshimi · Toaru Majutsu no Index · Base

Tier
HIGH 7-C
Attack Potency
Large Town Level
Speed
Average Human
Durability
Human Level

Mason cannon · Marvel · Base

Tier
HIGH 7-C
Attack Potency
Large Town Level
Speed
Massively Hypersonic+, up to Speed Of Light
Durability
Unknown

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