18-12-0 for More damage / Easy matchups (Anything Pre-D5 almost)
0-12-18 for Tank / Hard matchups
0-18-12 Stormraider's for Nasus/Slow stacking teamcomps

Bandit for all. Bandit will make it so that if you choose to focus on harassing your lane opponent with your e over csing, there will be no negative trade-off as you will be up gold from procing it up to 3 times on the spirit. It will also ensure that you hit item spikes such as Death's Dance as soon as possible, netting you pushing power and kill pressure.

As a side note, your passive tentacle swings on champions heal for the same amount as Dangerous Game.

Flat AD Reds, Spellvamp quints are my personal goto. Flat reds to CS and punish poor play early, Spellvamp to make your own poor play less damaging so you can stay in lane until a suitable back time or level 6.

Otherwise flat AD/Apen quints. Armor penetration scales better with your own damage, flat ad scales better with your e for team damage/setting up ganks.

Yellows are scaling Armor for most toplane matchups; midgame is all Illaoi is about. Otherwise scaling HP vs heavy AP and a non-punishing lane opponent or vs AP like rumble; I still take scaling armor vs Kennen.

Blues are scaling MR most of the time. If their team if full AD I take flat armor blues and scaling yellows. If they have a cheese toplaner like syndra/lissandra or something of the sort I take flat MR blues.

Max e. It is your primary source of tank through the extra sustain it gives, primary source of damage, sets up ganks, punishes laners, better for teamfighting, baiting tool, ensures a swing and extra tentacle for ult. People generally max q to afk push their tower and to clear the backline when they get black cleaver. However, I rush Death's Dance so level 1 Q at 10 minutes will clear the backline, level 2 clears backline regardless of the match time.

Q max next for the % damage increase on tentacles.

W max last as it only gains ~15 damage per level, and our ult reduces the CD of it to a flat amount regardless.

R level whenever possible.

Starting Items:
Corrupting Pot vs spell damage
Dshield for autoers, choose between red pots or refillable pot; red pots offer more security in lane/effective HP, refillable is just gold efficient after the first back.
Item Pathing:
- If laning is going fine, get AD. Backing with 1100g always go for hammer, backing with less go pickaxe for better item pathing later on, even less, stack longswords.
- Laning is poor, you have been pushed back and have no tp, go boots to get to lane faster. Lane faster = more cs, less damage on your tower, more exp, faster midgame.
- Laning vs Trindamere, you need to choose between getting an executioners or warden's mail, obviously go mail if you are losing and have no jungle pressure.
- Laning vs Vlad or Swain, get executioners, it procs on them with your spirit and is the only way you will be able to regain any of that early pressure that you lost to them in lane.

Losing Hard? Get an armor/mr component for one of your next core items then continue building Death's Dance. Warden's Mail or Cowl.

After Death's Dance:
Consider picking up your tier 2 boots, I only do so if I really feel like I need the % reduction on autos or tenacity, otherwise it is fine to leave them as tier 1 forever if you have really good gold values for picking up core items.

You now have infinite pushing pressure if you didn't give it all away to your opponent; you need to build for the strongest members on their team, not your laner as you will win all 1v1 skirmishes regardless.
Burst Champions and high support CC (AD damage mostly): Go sterak's
AP: Go Visage
ADC: Go Randuins
AD top/when team and you are snowballing out of control: Go black cleaver

Second Item:
Normally would be another tank item, if they are stacking armor and you believe you need to do more damage to siege or peel for teammates, go black cleaver.

Third Item:
If not black cleaver go a third tank item if you really feel it is necessary, consider picking up a GA.

Here you should be looking to see if picking up a Elixir of Wrath is best. I.e when you are pushing for an objective like baron or sieging, otherwise just build towards more items.

Anything after is whatever, you have hit your maximum power at 3 full items, if you haven't picked up black cleaver do so. If you are holding an executioner's upgrade to mortal reminder; if team has morrellos/executioner's consider swapping it out for a black cleaver. Black cleaver does more damage and has more utility if you don't need the unique passive from executioner's.

When GA is on cooldown you can sell it for a zzrot for the exact same resistances, however it is normally better to sell it for the bigger tank items like Banshee's or Dead Man's. I like to sell boots for Dead Man's plate. If you need to peel for carries you can sell boots for a non-mobility tank item, otherwise you need that initial mobility to atleast proc your black cleaver passive to not get kited in teamfights forever.

In all matchups in toplane, Illaoi can only look to trade and set-up waves post level 3. If you have jungle communication, make sure you are level 2 before they look to gank as you do next to 0 damage and have no cc level 1 and the gank will result in you losing exp and wasting jungle pressure and time.

Levels 1 through 3 are mostly the same for every game. Don't take too much harass for cs. Don't look to chunk with your e level 2 as you simply do not do any damage and it costs a lot of mana. Level 2 you should only be pulling with e if they are aggressively trying to trade with you, and only when adjacent to 1 or 2 tentacles. Q for last hits if you need to but try not to push the wave as it will be easier for them to punish your bad early levels and harder for you to stay near your caster minions to cs.

Most of the time you can look to take semi-extended trades with opponents if you land your e near a tentacle; always look to take down the spirit if the opponent is fleeing and you have no kill pressure chasing as minions will do more damage than you would auto and q trading in most circumstances.

Look to maximize you exp, never be in a position where you are forced to back after taking a trade for cs or 1v1; your 6 is the most powerful spike in her kit and contains all of her kill pressure without them messing up or you having jungle pressure.

Post level 6 and after your first tp back to lane you will probably be looking to generate as much pressure toplane as possible by afk pushing the wave and trading, drawing as many people to your lane as you can. Ward aggressively. Always TP back to lane whenever possible during laning phase if your botlane is trading even or not snowballing. Even when they are snowballing, if they have no hard setup cc for your teleport it is not worth giving up lane pressure as you offer nothing to most counter-ganks.

When your ult is off cooldown is the only time you can look to all-in or chase enemies. It is your only source of guarenteed dps and winning skirmishes. Aside from it being off cooldown, if your e is on a high cooldown you should not be looking to pressure your opponent, 1v1 ulting, generating only one tentacle, before you can pull with e will often not be enough to kill your opponent and will often lead to your death.

Look to push towers as hard as possible and figure out whether your team has the waveclear necessary for you to keep on splitting. Generally only split when there are no big objectives up on the map like dragon/tier 1 towers that you are able to siege with your team.

Rift is often never picked up as you do not do enough damage to kill it fast enough where the trade-off of pressure on the map and in your lane is worth the time it took for the buff. Rarely, but if objectives are down and their team is topside or mia, rift is a good team objective.