> Welp i know what ending happened in the Rp's world now it's robin beat grima correct not chrom beat grima?

Since there was a spoiler with Grima returning... Then I think it's Chrom slaying Grima.

But by that Canon it doesn't make sense since it's only 70 years past, when Naga stated that in another millenium, Grima would re-awaken.