I was watching Urgots special interactions:
https://www.youtube.com/watch?time_continue=1088&v=0wOh_BJFpAA
and I noticed that when he executed Sion and Kog'Maw that they didn't get their death passive after his ultimate execute. Was this edited out or is this a feature of his ultimate?
11:21 for Kog'maw
13:42 for Sion
On another note; if this is so, does it prevent things like GA and Zilean ultimate?
TheLastShadow452 votesMy brother and I just got done playing around with him and can say that no, he does not prevent death passives.
StoryDuck2 votesGood to know. Thank you. That video is very misleading though. Part of me is sad, I think that would be a really cool unique feature of his kit if it was "True Death"
Doozku1 votesEven more ways to counter 
midnight oil241 votesEh, Karthus could still work. Remember that he becomes a ghost in his passive, so even if he loses the body he can still do his thing.
Doozku1 votesRemember that consistency > logic in this game. Why can a giant wave be evaporated by a a wall of wind, when half of the wave didn't even touch it? Because gameplay reasons. If the other death passives were disabled, it wouldn't be fair if this one wasn't. And since there are only 3 death passives in the game, and only one of them is good, it would be pointless to add this "true death" mechanic gameplay-wise, tho it would be fun and make sense lore-wise (But lore wise Kog'maw would probably blow up inside Urgot's grinder, and how does Sion fit in there?).
midnight oil241 votesFair point. I was just mentioning that since his passive doesn't require a body then the grinder technically wouldn't work if it were real. Dumb thinking, I know, but still.
FlameanatorX1 votesIf it does prevent things like Kog passive, there's no way they'll let it disable revives, at least not without explicitly spelling it out. That's just waaaay too gamebreaking compared to preventing a couple hundred true damage to 0-3 champions.
Subject 51 votes
What if she ults?
What if he ults?
TheLastShadow451 votesthen the target wont die. It's simple.
Subject 51 votesthen the target wont die. It's simple.
Was this tested though? Because in most cases regardless of shields - they will still die.
TheLastShadow451 votesWas one of the things my brother and I did.