Solar Flare vs Motaro: who would win?

Solar Flare favored — Slight edge (~55%)

Solar Flare · Plants vs. Zombies · Base

Tier

2-C

Attack Potency

Low Multiverse Level

Speed

Massively Hypersonic, up to Relativistic+

Durability

Low Multiverse Level

Motaro · Mortal Kombat · Armageddon

Tier

2-C

Attack Potency

Low Multiverse Level

Speed

Superhuman, up to Sub-Relativistic

Durability

Low Multiverse Level

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