Question about Illaoi's E

Hello,

At risk of sounding negative, I'm confused about the gameplay/counterplay/design of Illaoi's E.

"Illaoi casts a spell that sends tendrils out in a target direction. If the tendrils connect with an enemy champion, they grasp the champion’s spirit and tear it back to Illaoi. When spirits are attacked by the Kraken Priestess or her allies, it transmits a portion of its suffering to their now spiritless champion. If Illaoi and her allies are able to destroy the spirit, or if the spiritless champion flees too far from their spirit, they suffer a heavy slow as they become a vessel, and start spawning tentacles around them that attack both their host and their allies. Test of Spirit allows tentacles to occasionally swing at spirits and vessels, dealing physical damage to all enemies hit."

From what I can see in the clip, the projectile seems to have similar speed and range to 's Q (snare).

My question is the recommended action if struck by this ability is not clear. Yes, I suppose it's "nice" that you are able to move at all (unlike a snare or stun, although I have no qualms with snares or stuns - being either hit by them or not being hit, is the exciting part, not the after effect), but the gameplay vs. consequences are confusing to me.

The enemies choose between chasing you down, or killing the spirit, but either one of these things will cause you to incur the slow & tentacle spawn. So are you supposed to...Not..run away? Are you meant to try to confuse the enemies between chasing you or attacking the spirit? Or are you supposed to try as hard as you can to run away, knowing full well that you will incur the slow + tentacles regardless, but that is simply your best option after being hit? (I assume you de-spawn the spirit if you go out of range - it does not say.)

My point is that with other abilities in the game that have some kind of "post-counterplay" - i.e., you have already been targeted by the ability, but now it's up to you to do what's best for yourself and your team - for example, if a Brand ult is targeted on you, you can intentionally run away from your team to delete the projectile on yourself.

Illaoi's makes me think of, for example, if 's snare had an extra effect in the ability which was, "Also, if you break LeBlanc's tether range, you also take damage and incur a movement speed slow." So you're like, "O...kay...? So what's the correct thing to do if I'm taking the damage either way?" If I'll be taking damage regardless, it seems strange to give the player "if/then" options regarding breaking the spirit range, etc.

Clarificiation/thoughts appreciated. I realize I might just be misunderstanding or missing something.