Poppy Is Killed By Zilean Bomb With Ult On Xin Zhao

I find this a bit strange and am pretty sure this is not one of League's "features"- so Zilean had put the bomb on Poppy before she ulted. The bomb had not gone off yet and she put her ult on Xin and should've only taken damage from him. That was not the case as mid ult Zilean's bomb had killed her. Here is the match in case that helps:

http://matchhistory.na.leagueoflegends.com/en/#match-details/NA1/1578819015/218937473

I don't think this should work as it takes away the whole point of Poppy's ult so if you could fix it that would be swell! :D