> > > > 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.
> > 
> > robin is only found in a field the second time in the robin beat Grima ending the chrom one is different you don't go away and appear in the field.
> 
> Does that make Robin beating Grima the technical true ending then?

Yep, that's the canon here. Because Robin would do it, he's that selfless.