Summoner spells

Flash
> Objectively the best summoner spell. One could make a case for Ghost being better for chasing, but that just doesn't change how powerful this spell is. Get it, every game.

Exhaust
> Its a toss up between getting this or Ignite. Exhaust is better most of the time though because it helps chasing, escaping, dueling, really almost any situation versus adc or no. Ignite is just more damage and healing reduction, which is only ever more useful than Exhaust in certain matchups.

Ignite
> Some would say this spell is quite aggresive. Those people would be correct. This spell gives much more kill potential in lane, but you generally want to only use it versus enemies such as Sona or Soraka as it'll mitigate their healing. But Exhaust is more useful in more situations, especially versus an adc.

Heal
> If for some reason your adc took Exhaust, then it's best to get this. Unless of course you're running some weird cheese strat with them, but by that point my advice is irrelevant.

Guide Top
Skills and Gameplay

Passive: Prophet Of An Elder God
> TENTACLES! That's this passive. Tentacles really don't do much by themselves and rely on Illaoi's abilities to actually be helpful. Tentacles spawn roughly every 20 seconds, and they position themselves on to the nearest wall to Illaoi, unless there's another tentacle nearby. The minimum distance between tentacle is just under the width of the lane. You can use this info to help positions tentacles in ideal locations, such as in or out of bushes, by specific sections of wall. Where you position a tentacle may give it more survivability if it's behind your minion wave or be useful for baiting an enemies actions if it's farther up the lane depending on the circumstance. Tentacles won't attack champions without Harsh Lesson, but can hit them if they happen to be in the area of another target they are hitting. Tentacles WILL attack spirits and vessels from Test of Spirit though. So when you land a spirit pull it's ideal to be in range of a tentacle as it'll immediately attack the pulled spirit. It's worth noting that tentacles are really easy to destroy once you leave them alone so don't be surprised if your enemy clears a few of them out if you leave lane while they're still hanging about. It's not too big a deal, since they're just as easily replaced as they are destroyed.

Tentacle Smash
> You do damage, in a line, and it heals you a bit. The active is really pretty simple and there isn't much to talk about in regards to it, but the main reason we get points into this is actually the passive, not the healing one but the other one it doesn't say, which increases the damage of all tentacle attacks. This is great since it bumps up the damage from all of your other spells indirectly as they all involve tentacle smashes. Having a second point in this before you hit level 6 is really valuable due to the immense damage spike gained from Leap of Faith. Also the actual passive is handy for lane sustain, since it also works off of tentacles summoned by Test of Spirit.

Harsh Lesson
> This is really good for bringing the smack down. You ideally use this after either: Test of Spirit makes a pull and you're beside a tentacle, so you get two tentacle smashes, one from the spirit naturally and the other from Harsh Lesson, as well as harsh lesson's base damage. The second time to use this is immediately after Leap of Faith and I cannot emphasize this enough: DO NOT USE HARSH LESSON TO GAPCLOSE FOR LEAP OF FAITH. You need Harsh Lesson up the moment you land Leap of Faith otherwise you are wasting all of your damage and sustain. Just be a woman, and walk up to your enemies or Flash if you have to, but whatever you do don't waste Harsh Lesson before Leap of Faith.

Test Of Spirit
> This essentially operates as Illaoi's hook and her most powerful zoning tool. It doesn't go through minions so you want to position yourself close to the lanes sides so you can throw it around the minion wave. If you land a grab one of two things will happen, either the enemy will fight you, or they won't. If they don't then obviously you want yourself and the adc to just chip away at the spirit super fast and kill it. It gives a lot of free poke damage for very little effort. If the enemy does fight you then you wanna determine if you can fight them before either going at em or running away. If you choose to fight them hit the enemy directly instead of the soul you pulled. If you can hit the soul and the enemy at the same time that is amazing as the damage amp is huge, but just attacking the soul by itself is stupid if you can't finish it off in 1 second. A handy tip for landing this in lane is to watch as your enemy goes to destroy your most aggressively placed tentacle, and then pull their spirit mid auto attack to the next tentacle down the lane.

Do not max this first because you need to use your q to do the real damage. This is great for Illaoi as by putting levels into tentacle smash will do a lot of damage. When you get to mid game it's super valuable for making picks as your whole team can burst it down in a second and the slow + tentacles makes life very difficult for your victims.

Leap Of Faith
> The heavy hitter. This is an ability which gets stronger the more enemies are under it, and in turn makes Illaoi great at turning around would-be lethal ganks. Combined with Harsh Lesson the burst and sustained damage on this is massive and each tentacle procs her healing passive from Tentacle Smash helping her survive the damage enemies will be pouring onto her. If you can, land a Test of Spirit before you ult, as the spirit will not only amplify the damage done to one poor soul, but it also counts as a champion when Leap of Faith summons it's tentacles, giving you one more friend to help pound you foes into the floor. In terms of geography, Leap of Faith is at it's most devastating near walls and in cramp spaces where the enemy has little room to escape. The smaller the space, the more tentacles overlap, the more mincemeat you make. This ult wins teamfights and games.

MLG PRO TIP: If an enemy is a vessel and is escaping at low health you can cast Leap of Faith while they are escaping. Doing so will cause all tentacles, including the ones spawning around the vessel, to swing 50% faster and be invincible for 8 seconds. This makes the tentacles that follow them not only harder to dodge, but harder to remove as well. This is great for sniping kills that would otherwise be impossible against cautious opponents.