I heard Yugi saying "So back off! Or we're gonna have a problem!" is not in the original dialogue. Is that true?
It’s not, but…
my heartshipper self is just as #alive as ever *coughs* I mean it’s still good!
Also, maybe I’m wrong, but I feel like the sentiment must have resonated with Kaiba, because this and not a threat are what got him to relent and let Yugi have his duel against Diva.