Ant-type Kaiju vs Ken Kaneki: who would win?

Ken Kaneki favored — Slight edge (~55%)

Ant-type Kaiju · Kaiju No. 8 · Base

Tier
7-C
Attack Potency
Town Level+
Speed
Subsonic
Durability
Town Level+

Ken Kaneki · Tokyo Ghoul · Post-Rose Arc

Tier
7-C, up to HIGH 7-C
Attack Potency
Large Town Level, up to Town Level+
Speed
Massively Hypersonic+, up to Sub-Relativistic
Durability
Large Town Level, up to Town Level+

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