Some quality of life changes to try to bring Illaoi into the modern game (suggestion)
I'm one of the highest ranked Illaoi mains in the world. I was briefly the highest elo Illaoi in the world at the start of the split, peaking at 436lp and rank 1500 overall for the EUW server. I mostly play stormraiders surge on her but I also play grasp, which is objectively stronger but also boring.
Illaoi as a champion feels very dead in high elo. This is because people stand outside your range and CC and kill you, basically. Her worst matchup, Varus top, does all of these things.
Because I'm aware she's a bit of a pubstomper, I understand that people aren't interested in hearing about "Illaoi buffs" (although she does regularly get changed anyway) but I thought I'd suggest some minor touchups she could use that relate to her kit being outdated or inconsistent.
The first change relates to the distance tentacles are able to spawn from eachother in toplane. When the map was changed a while ago, it became harder to spawn tentacles opposite eachother on walls (especially near turrets on either side). The lanes are just too narrow to get the right setup a lot of the time. I'd suggest slightly lowering the required physical distance between tentacle spawns to make it easier to set up two tentacles opposite eachother.
The second change relates to what happens when Illaoi dies. When Illaoi dies currently, tentacles stop slamming the vessel (the curse lifts). However, if the person becomes the vessel after Illaoi dies, they get slammed normally, which in some situations makes it counterproductive to kill the spirit if you are going to die soon after - you might as well let your tentacles kill it later because you will get more slams that way. This is a remnant of when her curse used to be 60 seconds long. Since the curse is only 4 seconds now, I'd suggest getting rid of the curse vanishing on death, especially since it currently works pretty inconsistently.
The third change relates to tentacle spawns on Nexus turrets. Currently, if the enemy is sieging your base and will take the inhib and pressure to end, you cannot set up tentacles until they have taken the inhib (meaning you will have at most one tentacle to defend Nexus turrets). So far as I'm aware this applies to all structures that are not yet able to be attacked. I'd suggest allowing her to set up tentacles to defend the base before an inhib is taken so she doesn't get caught flat footed by a quick enemy push. She's supposed to be the "setup a zone and fight" champion but because of how the modern map works she can't do this in the base.
The fourth change is making Illaoi slams count as "ability damage". The rune which seems to make most thematic sense on Illaoi is conqueror, but Illaoi can't really stack it because her slams don't count as ability damage. If you think about it, her non-passive slam abilities don't actually get cast that often, most of her damage is done with those slams. Most fights with conqueror, Illaoi finishes stacking at the very end, which just feels like a gut punch when you get the "stacked" sound after the fight is already over. If passive slams counted as ability damage, this would help move her away from the obnoxious grasp W spam variant and give her a bit more to do in fights with conq being an option.
The last change is to how the dash version of W (non melee version) works. For those who don't understand, Illaoi has 2 versions of W, a melee version which acts as an auto-reset and the ranged version which dashes. I think it would be a good idea to make it so that if you flash during ranged W, the damage and slam effect still goes through, as if you cast the melee version. Basically you have to be careful repositioning with flash as Illaoi as it stands because you can heavily grief your own damage by flashing during the W dash windup if it's the ranged version of W you're casting. This change would help make her more dynamic in skirmishes.
Summary of the aim of the changes I've suggested: make tentacle setup a bit less clunky, make her w feel a bit less clunky with flash, reward you a bit more for killing the spirit in tight situations, give her another keystone option which she's been somewhat locked out of.
