Ilaoi Is Kinda OP. TL;DR I know, but please its worth the read.

Now before you dismiss this as another rant by a bronze scrub, who can't deal with a new champion, allow me to present my case. First of all, Im not high elo, Im currently Gold 3 and I know that my opinion has little weight, However, There are some big issues about Illaoi and her kit that need to be addressed.
In my match, I played Jayce vs Illaoi top, and did great in laning phase, I went 5-1 with a 3-0-5 kha jg, and shut down this Illaoi entirely. and Yet by the time she completed frozen mallet, I was completely unable to duel her anymore. As I dived on to her with my Q, she could retaliate with an easy landing E +Q(on to my soul) and an ult smash, while 5 tentacles, decimated both me(full hp) and my full hp jg. The snowball only got worse from there. Even laning was insanely difficult, the only reason I won lane was because my enemy was bad and went for failed turret dives early. Anyway, enough ranting that was the situation. Basically the problem is, she went from 1-5 to 9-5 in a matter of minutes.

The biggest strength, and OP(to the point of unfairness) about her kit is probably her E. I understand that its vital, to her kit, however the fact of the matter is, seeing as top is full of melee champions, having to get close to her to do damage grants access to easy reliable Es, which also have pretty good amount of RANGE. Secondly, you cannot escape it, Leaving the range of her E means almost leaving lane entirely, and that is to lose all of the experience from the dying minions. Third, even when you leave the E's range, you arent safe, running away leads to the 90%slow, and you to become a Vassal, and tentacles to spawn around you, also considering that the effects last almost 7-8 seconds, if you barely managed to escape her, That is a total 7-8 seconds more that you CANNOT RECALL or go to safety. Fourth, Seeing as her tentacles naturally allow her to push lane, once her E is landed, choosing to fight her to push her away from your soul, means 1) Diving in to fight her, in her territory (i.e surrounded by tentacles) 2) Having to fight her within her own minion wave and 3) Having to fight her herself. In any early game scenario, fighting among enemy minions is a bad idea, that is common knowledge. Essentially her E forces you to make an unfavorable fight , or run and face the consequences of being a vassal. THIS LEADS TO POINT FIVE, Fifth-> When you are forced to back out due to not having the ability to make an unfavorable fight, you are stuck trying to 1) dodge her tentacle attacks, 2) remove the tentacles so you dont set yourself up for a turret dive W and 3) Trying to farm that minion wave she conveniently pushed with her Q and passive.

All of my complaints would be less meaningful if her damage was reasonable, but especially when she hits 6, getting tagged by an E+R+W is almost a guaranteed death. I really enjoy the concept of a zone-controlling tank, it is the kind of play style I have long since waited for in League, However Illoai offers too little opportunity for countering, especially if you are playing Early game strength champions like Riven , or Jayce.

One potential nerf would be to consider allowing you to escape her E range without becoming a vassal, In turn, that way enemies are given the opportunity to potentially escape an unfavorable scenario, But That would make her too weak, to compensate for that, They could make her W a slow, or a conditional snare of some sort, That way, The effectiveness of her E is held when she can E the enemy then CC them with the W inorder to damage the soul, while a good reaction from an enemy who got hit by an E, but managed to escape the CC, could be rewarded with a brief respite.