Toadette vs Karsus: who would win?

Toadette favored — Slight edge (~55%)

Toadette · Super Mario Bros · Base

Tier

HIGH 6-A

Attack Potency

Multi-Continent Level

Speed

Massively Ftl+

Durability

Multi-Continent Level

Karsus · Dungeons & Dragons · Archwizard of Netheril

Tier

HIGH 6-A, up to 2-A

Attack Potency

Multi-Continent Level, up to Multiverse Level+

Speed

Relativistic+, up to Infinite

Durability

Multi-Continent Level, up to Multiverse Level+

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