When E lands, do not auto-chase; take a small step back while hitting the spirit so they have to either give ground or walk forward through your tentacles to contest it
In grouped fights, a clean spirit on the front line beside a wall is often the right play, because Illaoi can echo real pressure through that target and she wastes R if she stands still instead of moving and cycling W
Illaoi’s best games usually come from turning side lane into a bad exam for the enemy top/jungle pair, since recent data and mains discussion both point toward punishing bad 2v1 answers on her prepared walls far more than leaving her setup to roam
Ult once the fight has already committed into your space, not just because someone is in range. The best casts usually happen after a clean E, when at least one enemy has to stay close, or when a gank turns into a pileup around your tentacles. If you press R too early on bare ground, people can just step out and you spent your whole threat for almost nothing. In lane, that often means waiting for the opponent or jungler to take the extra step in. In skirmishes and teamfights, it means valuing the cast that traps people in the mess over the cast that merely starts it.
Illaoi and the Vessels she creates spawn Tentacles on nearby impassible terrain. Tentacles swing at spirits, Vessels, and victims of Illaoi's Harsh lesson. Tentacles deal physical damage to enemies hit, and will heal Illaoi if they damage a champion.
Increases the damage dealt by Tentacles. When activated, Illaoi smashes down a Tentacle that deals physical damage.
Illaoi leaps to her target, dealing physical damage and causing nearby Tentacles to also swing at the target.
Illaoi rips the spirit from a foe's body, forcing it to stand before her. Spirits echo a percentage of the damage they take to the original target. If killed, or if the target gets too far from the spirit, the target will become a Vessel and begin spawning Tentacles.
Illaoi smashes her idol into the ground, dealing physical damage to nearby enemies. A Tentacle spawns for each enemy champion hit.