Upon arrival, Lillie and Hapu will finally catch up with you. Lillie will helpfully heal your party and, after that, you're feel to continue. Start by making your way up the long, long flight of stairs. Call up Tauros and charge straight to the top if you're in a hurry.
At the summit, Lillie will head over to the west side to play the Moon or Sun Flute, depending on which version you're playing. You should go north-east towards the corresponding square on the opposite side. Step in the middle and you'll be asked to play the Sun or Moon Flute.
So the legends were true. The Legendary Pokemon of Alola--Solgaleo in Pokemon Sun and Lunala in Pokemon Moon--does indeed exist. Why are we not surprised in the slightest? Not only that, but the Legendary Pokemon can help you reach the world of the Ultra Beasts...
Follow the path north to where Lillie is. You'll bump into an unfortunate guest who's got a clear message for you and that's to stay far, far away. However there's no way you're turning back after you've come this far. So continue ahead. You'll find what you're looking for...
Aether President Lusamine
Lusamine's party is completely unchanged, but her Pokemon all have much better moves, as well as auras that boost their stats. This is your toughest battle yet, so you need to bring your A-game.
Clefable is the same bulky Fairy-type as before, but now has more Special Defence and Moonlight to restore HP. End it swiftly with strong Steel or Poison-types or try to power through with a Fire-type to resist Moonblast.
Milotic has an Attack boost, which is pretty much useless, except when it uses Flail as a last resort. The biggest change is Recover, which allows it to restore HP. As before, tank it with your Grass-type powerhouses or, failing that, Electric-types.
Mismagius receives a Speed boost, which is nasty since it's pretty fast to begin with; expect it to go first unless you have an even speedier Pokemon. On top of Ghost, Fire and Rock-type moves, it has Pain Split, which shares out HP. Smack it with your physical attackers.
Bewear has increased Defence, so bad news for your physical attackers. Like Mismagius, it has Pain Split, which is annoying if it survives with low HP; otherwise it's nothing to be afraid of. Like before, take it out with your special attackers; especially those that resist Fighting.
Finally, Lilligant is a beast with boosted Special Attack. In addition, it has Leech Seed to slowly make fun of your Pokemon. Destroy it with your speedy Pokemon resistant to Grass before it gets a chance to sweep the floor with Petal Dance.
Altar of the Sunne/Moone
After that tricky battle, you've got a different kind of tricky battle ahead. Approach Solgaleo (Sun) or Lunala (Moon) to begin an epic battle to ensnare the Legendary Pokemon! By the way, if you're not ready, you can leave now and use Charizard Glide to come back.
|Solgaleo (if playing Sun)||55||Steel/Psychic|
|Lunala (if playing Moon)||55||Ghost/Psychic|
First things first, it shouldn't really be a surprise, but both Legendary Pokemon are capable of dealing a truckload of damage. Especially if they use their signature move--Sunsteel Strike for Solgaleo and Moongeist Beam for Lunala.
Therefore we strongly recommend fielding at least one Pokemon that can resist the Legendary Pokemon's moves. For Solgaleo, Steel-types are good to resist Sunsteel Strike and Zen Headbutt. But you'll have to watch out for the Dark-type Crunch.
Meanwhile, Lunala specialises in Ghost-type and Dark-type moves, so a Dark-type is ideal. The next thing you should do is try to inflict a status affliction on the Legendary Pokemon. Paralyse is good since it lasts for the entire battle, but Sleep offers a better catch rate.
For Solgaleo, Paralyse is preferred since you can't decrease its stats due to its Full Metal Body Ability. At least with Lunala, you can decrease its Special Attack using Snarl or other means. Which you should aim to do to make the battle much easier.
Both Pokemon have Cosmic Power, which boosts both defence stats. On top of that, Lunala has Shadow Shield, which reduces damages while it has full HP. Be sure to take that into account, as you might accidentally overshoot on the second hit, thinking it's bulkier than it really is.
The general strategy is to try and outlast the Legendary Pokemon, using resistant Pokemon where possible and reducing its stats or causing a status ailment. After that, you slowly whittle down its HP like any other Pokemon, trying to get it as far down as possible without fainting it.
Oops, That Wasn't Supposed to Happen
If you accidentally KO the Legendary Pokemon, don't panic as you'll be allowed to try again. In fact, you can try as many times as you'd like. You won't be able to progress the story until you've caught it, but it shouldn't take more than a few attempts at the most.
If facing Solgaleo, you can use False Swipe to safely reduce its HP, although it'll barely do any damage unless you boost your Attack. Meanwhile Lunala is immune to False Swipe since it's a Ghost, unless you have Foresight (Decidueye can learn both) or Soak etc.
Once the Pokemon's HP is low and it has a status affliction, it's time to start chucking your Poke Balls like no tomorrow! Both Pokemon have a decent catch rate, so you shouldn't be there all day. You do have the Master Ball, but there's little point using it for something this easy.
By the way, even with resistant Pokemon, the Legendary Pokemon can still do substantial damage, so don't hesitate to use healing items. You can also give your main Pokemon Leftovers stolen from the Munchlax on Route 1, which gradually restores their HP.
Tame the beast and you'll be invited to the final trial on Ula'ula Island's Mount Lanikila. If you want, you can be whisked straight there; it's up to you.
With Solgaleo or Lunala by your side, you should have a far easier time defeating the remaining trainers in your path. In fact, you might find it too easy. Which isn't a bad thing at all, but for those looking for a challenge, you may want to keep them to the side for a while.