- 99
- 110
Looking more into it, and I can't find anything that contradicts UFO Robo Grendizer vs Great Mazinger being canon to the Toei shows. The Infinity movie supports it and there's a manga chapter that tells the same story again. Post original anime Mazinger Z, Great Mazinger and Grendizer should all scale to each other just fine. This means their strongest keys will fall on Tier 6 most likely because of a very impressive Grendizer durability feat. Manga versions should follow the same logic, but with all of them upscaling Mazinger Z's hydrogen bomb statement.