Pokemon Legends Arceus: The Sea’s Legend & how to get Manaphy

The Sea’s Legend is one of the most curious side quests in Pokemon Legends Arceus. Of all the request side quests in the game, it’s one of the most puzzling and difficult to figure out - in part because it requires you to be familiar with a clue offered up in a completely different game!

Once you catch an Overqwil for the first time or as you approach the late game, Professor Laventon will offer up this quest in Galaxy HQ. The quest text is mysterious, reading: “The Pokemon that Professor Laventon saw in the ocean might be connected to the Pokemon that appears in “The Sea’s Legend”..."

On this page, we’ll puzzle out that clue for you and explain how to beat Quest 66, The Sea’s Legend, which in turn gives you a new Mythical Pokemon, Manaphy. It’s simple when you know how - naturally - but it’s also one of the most complicated side quests in the game.

The Sea Legend Guide: understanding the quest's solution

The story of 'The Sea's Legend' as told in a book in Pokemon BDSP.

To understand The Sea’s Legend in Pokemon Legends Arceus, we first need to refer back to Pokemon Brilliant Diamond and Shining Pearl, the remakes released just a few months ago. A clue was quietly dropped into that game, and now it comes to fruition in Legends Arceus. 

BDSP and Legends Arceus are set in the same region, just hundreds of years apart - and so the book in that game, also titled ‘The Sea’s Legend’, is a perfect clue for the quest of the same name in your Hisui adventure. 

Here’s the text of ‘The Sea’s Legend’ in Pokemon BDSP:


Once upon a time in the East Sea, there was a Pokemon known as The Prince. A brave human asked the Pokemon living in the sea to let them see the prince. Mantyke, Buizel, and a Qwilfish with huge spikes acknowledged the human’s bravery and joined them. 

Together, they set off in a boat over the sunset-streaked sea, sailing through the ocean gate stretched over the waves. News of this reached the ears of the prince, who went to meet the brave little party at the Seaside Hollow

From these clues, we can now understand what this quest requires us to do; we’re going to act out the story in the book for real. 

The Sea’s Legend Walkthrough

Professor Laventon talks about the mystery of 'The Sea's Legend'.

To complete The Sea’s Legend, we have to copy the steps from the story above, recreating them yourself to fulfill the story of The Sea Legend.

In short, here’s what to do to complete the side quest:

Gather Three Pokemon from the Sea's Legend

  • First of all, it mentions three Pokemon by name: Mantyke, Buizel, and Qwilfish. You need to catch all three of these Pokemon.
  • You can catch Mantyke and Buizel easily in the Cobalt Coastlands beaches (Buizel) and water (Mantyke). You’ll also need to head further into the waters to find a Qwilfish - but that alone isn’t good enough. 
  • Once you have all three Pokemon, you need to evolve Qwilfish into Overqwil - a new Hisuian form that is hinted at with the comment about huge spikes. To do this, take your Qwilfish and use the ‘Barb Barrage’ moves in Strong Style 20 times. This can be over multiple battles, of course. Once you have done this, you’ll have the option to evolve Qwilfish to Overqwil as described on our Pokemon Legends Arceus Evolution guide.
An image of the location in the Cobalt Coastlands players must go to in order to continue The Sea's Legend quest.

Sail through the Horns of the 'Ocean Gate'

  • Make sure it's evening, as this won't work at any other time of day. You want that nice sunset. You can rest at the nearby Coastlands Camp to advance the time to evening. 
  • With Buizel, Mantyke, and Overqwil in your party, head to the large split gate that features at the end of the Cobalt Coastlands’s south-eastern land mass. Swim between it, and the game will react - you’ll hear a distant “Fiooooo…” 
  • This noise unlocks a new area on the Cobalt Coastlands. It’s a cave on the north side of Veilstone Cape, accessed via water, and it’s called… you guessed it, Seaside Hollow! Just like the story.

Inside this cave you’ll find Manaphy, the water-type mythical Pokemon that made its debut back in the original Diamond and Pearl. It’s accompanied by Phione, too, a similar-looking but non-mythical Pokemon. 

How to catch Manaphy in Pokemon Legends Arceus

Mythical Pokemon Manaphy at the end of Pokemon Legends Arceus's The Sea's Legend quest.

This cave is the only place in the game where you’ll find Manaphy or Phione, which means the only way to catch this pair is via The Sea’s Legend side quest. While the quest rewards you with 1 Comet Shard, the real reward is catching these two Pokemon for your Pokedex.

It’s not entirely easy to catch them, however - so a few key tips to keep in mind when you’re trying to catch Manaphy:

  • You don’t need to keep the Sea’s Legend trio in your party. Once the cave is unlocked, you can visit it whenever - so feel free to go back to camp and swap out Qwilfish, Buizel, and Mantyke if you wish.
  • You only get one shot at Manaphy, but Phione are endless. Manaphy is a mythical Pokemon, so a one-and-done deal. If you knock it out, you can come back to try again - but you can only ever catch the one. It’s the one with the yellow markings above its eyes. The Phione, however, can be knocked out quickly so you can focus on Manaphy. If you fail to catch one before Manaphy, when you return to the cave you’ll find Phione alone in here, so you’ve plenty of chance to get lots of them later. 
  • Be aware of Manaphy’s stats & moves. Manaphy is a water-type Pokemon and has the Acid Armor (Poison), Zen Headbutt (Psychic), and Moonblast (Fairy) attacks. It’s level 50. Consult our Type Strengths & Weaknesses chart to plan ahead.
  • Use distraction items to break Manaphy’s shield. It’ll be hostile the moment it sees you. As ever, use items like balls of mud or what have you to break the shield it summons, then toss a Pokemon to start battle. It’s not worth bothering trying to catch without battling.
  • Use Ultra Balls. While it’s possible to get to this quest before Ultra Balls are unlocked for your crafting recipes, we wouldn’t particularly advise trying to catch Manaphy without them. It’ll be hard work.

There's a few more puzzling quests in Legends Arceus, but we've got more guides to help. Visit our Pokemon Legends Arceus guides page, or try out our walkthroughs for the Snowpoint Temple puzzles, Bothersome Bidoof, the identity of the Three Leaf Pokemon, and the Uxie Trial.