What I love about M:tG is the fact that even after 10+ years of playing you always come up against new situations. This one stumped me earlier tonight though.
I've gone up against Leyline of the Void a few times over the years, but earlier I had mind controlled the Leyline's owners creature, then sacrificed it for an ability, pretty standard fare.
He immediately swiped back the card putting it into his graveyard and stated that I don't actually get any benefit for the sacrifice and definitely don't get to exile his creature from the Leyline's ability?
I said he was wrong based on my understanding of graveyard triggers. I thought that, even though I don't own the permanent, it still triggers graveyard entry, even if it essentially can't exist in my graveyard and goes to the owners. For example sacrificing a token still counts as a creature dying and entering a graveyard, even though they cease to exist after triggering entering the graveyard. So I thought his creature would exile even though he was the owner, I was the controller and anything that goes to my graveyard exiles?
It was late and we agreed that he was right to move game on, but ironically the 2 judges in our group had gone by then and I think he just wanted to keep the card in his graveyard so he could recur it. So was I wrong to challenge him? Just having and playing a card doesn't mean you know how it plays.