Haiji Towa vs Nightsider: who would win?

Haiji Towa favored — Slight edge (~55%)

Haiji Towa · Danganronpa · Base

Tier

9-A, up to HIGH 7-C

Attack Potency

Small Building Level+, up to Large Town Level

Speed

Superhuman, up to Relativistic+

Durability

Small Building Level+, up to Large Town Level

Nightsider · Warhammer 40,000 · Base

Tier

9-A

Attack Potency

Building Level+

Speed

Average Human, up to Speed Of Light

Durability

Human Level

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