Fireburn
BARN ALL
The only problem with this scenario is that this is BW2 Ubers, so it is impossible for Giratina-O to get a first-turn wake. For this scenario to play out, Zekrom would have to paralyze the Ghost Arceus with Bolt Strike, then Giratina-O gets a second-turn wake after Ghostceus FPs once.Tbf the whole "Gene not being Scarf and Problems has to crit twice" is hilarious. You could have come up with a much more probable scenario:
Giratina-O was actually the old school DPP mixed set (not used much any more but tbf it's more probable than non-Scarf Gene). Zekrom Bolt Strikes Ghostceus for >55% and then Gira-O comes in and one-turn wakes to revenge Ghostceus with Shadow Sneak. It then lives a Genesect Ice Beam and then kills it with HP Fire, picks off Latias with Shadow Sneak, and then finishes off Groudon with Draco Meteor.
I'm so good at this :P
You are correct in saying that this could be possible, assuming yellow magic intervention. :V