NERF ILLAOI !

Having played Illaoi a lot frequently, it's likely a skills problem. That ult can be useless without the right set-up.

Illaoi is a very situational champion. In the right situation, if she gets into the middle of 5 and lives long enough to get it off, hitting the E spirit and all 5 enemy champions gives her 6 tentacles and lowers her W's base cooldown to 2 seconds, allowing her to pretty much just tentacle rape the entire enemy team.

However, if the enemy team has enough stuns to lock her down or enough range to just spread out and keep their distance from her, she's just gonna die every time she tries to do anything at all. If Illaoi does get everything off right, you have made several serious mistakes: 1) you let her get fed. 2) you let her get into you. 3) you didn't stun lock her. If any one of these cases isn't true, she's completely useless.