Charlie Morningstar vs Leo Valdez: who would win?

Too close to call

Charlie Morningstar · Hazbin Hotel · Base

Tier
9-C, up to 5-B
Attack Potency
Street Level, up to Planet Level+
Speed
Subsonic+, up to Supersonic
Durability
Street Level, up to Planet Level+

Leo Valdez · Percy Jackson · The Lost Hero

Tier
9-C, up to 9-B
Attack Potency
Street Level, up to Wall Level
Speed
Transonic
Durability
Street Level

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