Popp vs Kakran Grandmother: who would win?

Popp favored — Slight edge (~55%)

Popp · Dragon Quest · Base

Tier
HIGH 6-A
Attack Potency
Multi-Continent Level
Speed
Relativistic+
Durability
Multi-Continent Level

Kakran Grandmother · Star Wars · Base

Tier
HIGH 6-A, up to 5-C
Attack Potency
Multi-Continent Level, up to Moon Level
Speed
Massively Hypersonic, up to Massively Hypersonic+
Durability
Multi-Continent Level, up to Moon Level

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