Hello!
My name is Delthion, or Basmadra in League. I have been playing Lillia since her release in 2020. I've recently gotten back into League and have been finding a high amount of success with her. In ranked this season I have an 83% winrate on Lillia. The sample size is rather small to be fair, but I think if you follow my guide you will have a high winrate and a lot of fun with this champion.

The most fun part about Lillia is that she's basically a better Singed: more mobility, more damage, and more tankiness if you play her correctly. Her ability to survive is unique in that it is almost entirely based on your movement. If you use spacing well, you can dominate most lane opponents. If you can't, or you're playing against a champion that doesn't let you space them, you'll probably lose. But that's okay, because my build allows Lillia to thrive no matter how you did in lane.

That's the beauty of building Lillia like this, you can go 0/5 in lane and still have a fairly decent impact on the game. You'll still do a lot of damage and, depending on the other champions, you might even be able to hold your own in the side lanes.

Pros:
Versatile, (damage dealer and tank)
Mobile
Game-changing CC in her ult
Really fun to run around your opponents
Can split-push or teamfight
Good into champions like Nasus, Singed, Garen, etc. (Fighters with lower mobility essentially.)
Loves fighting Melees
FUN

Cons:
Requires good spacing especially in the early game
Struggles to take turrets
Trading tends to push the lane
Struggles against tanky champions with hard-cc in the early game
Struggles against ranged champions

Now my runes may seem a little unorthodox to most people here. Conquerer seems to be the meta, but I just don't enjoy it that much. It doesn't feel as good as Phase Rush to play.
Phase Rush - Good rune to get out of or into situations fast. One Ability and an auto will proc it so be wary of that if you're trying to save it. The fact that it removes slows for the duration is the arguably the best part for Lillia. Offers mobility that makes it much easier to get out of sticky situations. Conquerer can't really help with this, which is why I prefer Phase Rush.

Manaflow Band - Helps with early mana problems which are huge. In an ideal lane we get control of the minion wave at level 1 by trading fairly heavy. This leads to a lot of mana issues which this rune helps mitigate.

Transcendence - Just an overall quality of life rune. The CDR is nice to help with keeping the passive Q movespeed up. I haven't tried Celerity recently, but I don't think it makes enough of an impact to warrant taking it over Transcendence.

Gathering Storm - This is the only rune that makes sense here. Fairly nice scaling rune that is better than the conditional damage that Waterwalking gives. The 20 damage from Scorch level 1 is also not worth trading it for Gathering Storm.

Presence of Mind - Probably my favorite rune in the game. It's incredibly useful at keeping our mana issues at bay. Lillia likes lane-bullying, this lets her do it better.

Legend: Tenacity - We want Swifties. Any other boot choice feels awful. This lets us do that and get some of the benefit from Merc Treads as well.

Liandry's Anguish - Definitely the best mythic for Lillia. When in combination with Presence of Mind and Manaflow Band it solves the mana issues that we have in the early game, and gives Lillia a nice steroid to her DoT.

Riftmaker - This item would be very nice for Lillia if we didn't need Lost Chapter's mana so badly. For that reason and the fact that it doesn't add to the burn damage makes it not as good as Liandry's.

Rylai's Crystal Scepter - A very nice item that makes Lillia a lot tougher. She survives through being faster than her opponents and her opponents' damage. This slows your opponent which is perfect for that. Once you get these two items and boots you'll pretty much be able to survive whatever melee champion gets thrown your way.

Boots of Swiftness - The best boots in the game for Lillia. She wants to move faster than other champions. So getting the fastest boots makes sense. The slow reduction helps A LOT in running away and toward the enemy. You'll feel the difference if you build either Merc Treads or Steelcaps, neither of them feel as good. But if you got counter-picked and are facing a Vayne or an Ornn, definitely adapt accordingly.

From here, I prefer building tanky because it let's you run around your foes even more. If you get into really chaotic teamfights, it will let you walk into the middle of the enemy team, press Q and R and win the fight.

Deadman's Plate - One of the best tank items for Lillia. I like building this if there isn't any particular threat on the enemy team that I need to be particularly worried about. It makes you faster. Fast is good. Fast is fun. More fast = more fun.

Abyssal Mask - Build this after Rylai's if they're threats are mostly AP. Shreds some MR for yourself and your teammates. Very nice item for Lillia.

Here's where I leave you for items. I trust that you can figure it out from here. Pretty simple really: Build Liandry's, Rylai's, and Swifties. From there you can adapt to what the enemy team is throwing at you. All AD auto attackers? Thornmail + Frozen Heart would be a good option. Against an incredibly fed midlaner? Force of Nature and Abyssal Mask would be a good option!

Laning Phase is where you will either have the most fun or the most suffering. Lillia likes to be a lane bully, especially at level 2. Your E is an incredibly effective tool to ensure your Q damages your opponent. It also gives you a lot of survivability. Your ideal trade pattern if you're not going for an all-in is E-Q to proc Phase Rush and run. They won't be able to get much damage back at you as you sprint away.

Try your best to keep your lane from pushing. This is very important, you want to harass your opponent. If there's a long lane behind you, they can jump on you and kill you more easily than if the wave was on your side of the map.

You want to trade as much as you can, but try to do it outside of the minion wave. If this is impossible, that's okay, just keep an eye out for their jungler.

All of this comes with a caveat that if you're facing a counter, (any champion like Lucian, or Ornn) you want to avoid trading so heavily and keep the wave under turret.

The best part is, that Lillia thrives not necessarily in stomping lane, but in making sure that your lane opponent is absolutely useless. Remember, even if your 0/5 and your opponent is 5/0 you'll probably end up outdamaging them and winning the game.

Ideally, you'll be in the sidelane continuing to harrass your lane opponent with your E. If you can do this, you'll most likely also be first to the teamfight if there is one. If the opposing team tries to collapse on you, just E to hit something and run. You don't have to hit a champion, just get the passive movespeed and hightail it out of there.

It's incredibly difficult to splitpush against Lillia due to her waveclear. you don't have to fight the splitpusher to make them irrelevant, just instaclear the wave under turret with your plethora of AoE abilities.

It's very hard to out teamfight a Lillia at most stages of the game. Your DoT and sleep are so effective at changing the tides of the teamfight that you will almost always be relevant no matter how hard you throw in the laning phase.

Remember, being there as a Lillia is usually more useful than being there as another champion that's 5/0. So keep an eye on the map.

This has been my Lillia top guide! I hope you had a fun time reading it. Now this may or may not be the optimal way to play her top. But in my opinion, it is the most fun way. And as long as you're actively trying to win, having fun is all that matters.

I hope this guide finds you all well.
Have fun out there on the rift!
Basmadra