Illaoi's too strong

So today while playing league i had to play verse 2 illaoi's, first game i was yorick (trying him out before his upcoming rework) and second game as my 2nd most played champion Quinn both in the top lane. As my jungler (zac) and my midlaner (yasuo) where going to come toplane to help me out with this monster so was their jungler (kindred) we managed to spot out kindred and kill her easy, but then illaoi (with a long sword, a ruby crystal and dorans blade) walks up to all 3 of us Quinn with caulfields hammer, yasuo with zeal and zac with stalkers blade(each with %90 hp and zac had his passive) and uses her ult, she just stood there not using auto attacks or spells other than her ult, all she did was taunt us the whole time..... while she got a triple kill and walked out with almost max hp. (this was norms btw)

this is taking the vayne 1v5 joke way to far. for all i know illaoi could probably 1v20 and still walk out with all her health. This really doesnt seem fair too people playing verse her, she presses one button in a team fight and sit there and taunt while everyone is dead (Taking the 1 button pentakill joke wayyyy too far also)

But also being on the opposite side of this, whats the counter play too this crap???? she will ult every team fight and just kill your team off quickly, she will grab your body and force you to base away/ zone you from farm with it like really unless your teemo you can't win this matchup.