Does Illaoi deserve a nerf ?

I know she has a stable winrate and all, but what is bringing me the idea that Illaoi might be a little too overpowered is that she has incredible sustain, little mana costs and she can 1v5. I did some games against Illaoi, she is really cancer to play against. Her Q makes her heal for 5% of her missing health each time a tentacle hits an ennemy champion. Last game I was jungle with J4 and I was with my friend Fiora which did good early against Illaoi. He kept complaining about how disgusting in lane she is. Then he told me that when she got her 2 first items, he wasn't able to handle her anymore. Then late game came, we saw Illaoi alone and we engaged her. She ulted us, and that made her an instant quadra kill... She wasn't even fed or anything. Her build was litteraly almost tanky items.She had only black cleaver and titanic hydra for bruiser items. So what I'm trying to tell is that we can nerf her damage for example, but add some utility in her kit. Her E is really annoying to deal with. It lasts too much time, when we get out of it we still have to deal with 3 tentacles trying to get us and preventing us from recalling or slapping us undertower.. In the game I was talking about she took my Ahri and my Miss Fortune with her E, when she and her team killed their spirit, those two were all under 20% health after only taking one E and not even a single damage from the ennemy team. So I would like to know what you guys think about Illaoi as well. Does she need a nerf? Some changes?