If I cast Hijack followed by Supernatural Stamina on an opponent’s creature and then I sacrifice it, I assume the following:

1) The creature comes back on my side, not my opponents
2) At end of turn, it does not return to my opponent, since it is technically a different creature than the one that was Hijacked.

Am I thinking about this correctly?

Probably want to post this in the Magic for Dummies thread instead (a few topics below this one).

I think you're incorrect. The owner of the creature will always be your opponent (you control it temporarily, but not own it), so the creature returns to your opponent's side.

That’s correct... “Under it’s owner’s control” you don’t get to keep it. Some cards do that combo properly though. But fwiw, it’s a bad combo... way too expensive for the effect. Better to just kill the creature with 1 card.

Fling it if Fling is in Duels.

Yeah it goes back to the owner. In Duels 2015 I had a deck that ran Act of Treason and Cloudshift combo, fun times.

The problem with this type of combo is that it completely ignores the possibility that the opponent may try to win without creatures (or play only creatures that are poor, even impossible, targets for the combo). It forces you to devote a large part of your deck to making it all work, and then it's completely dependent on your opponent's deck being prey to your goals. It's much better to just play removal, which generally cuts the amount of required card slots in half, and therefore doesn't simply roll over to control decks, or other alt-win conditions.

I ran the same combo and man it was FUN.