Zappa vs Bast: who would win?

Zappa favored — Slight edge (~55%)

Zappa · Guilty Gear · Pre-Xrd

Tier

6-A

Attack Potency

Continent Level

Speed

Relativistic+

Durability

Continent Level

Bast · Percy Jackson · Base

Tier

6-A, up to HIGH 6-A

Attack Potency

Continent Level, up to Multi-Continent Level

Speed

High Hypersonic+

Durability

Continent Level, up to Multi-Continent Level

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