Relentless Hunter doesn't actually show champions
I noticed this only a little while ago while playing as Annie but Relentless Hunter doesn't actually display usernames and champions, instead only showing their slot with tags like "SummonerName1" or "SummonerChampion9" etc.
Normally this isn't that big a deal but when you are getting further into the game and you have a single stack left you pretty much just have to take random stabs at who you haven't killed yet which can get a little annoying at times.