Grisha Yeager vs Amber (RWBY): who would win?

Amber (RWBY) favored — Slight edge (~55%)

Grisha Yeager · Attack on Titan · Titan Form

Tier

8-B

Attack Potency

City Block Level+

Speed

Subsonic, up to Supersonic

Durability

Building Level

Amber (RWBY) · RWBY · Base

Tier

8-B, up to LOW 7-B

Attack Potency

City Block Level, up to Small City Level

Speed

Massively Hypersonic

Durability

City Block Level, up to Small City Level

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