Defeated the Elite Four after earning all eight badges Have the National Pokédex available Have a Pokémon near level 70
Chespin - You’ll be able to catch Articuno. Fennekin - You’ll be able to catch Zapdos. Froakie - You’ll be able to catch Moltres.
If the bird is several cities over, flying to a new city in order to reset the bird’s location to be closer to you is a good strategy.
There’s no discernible pattern for the legendary bird’s travel routes. If you pass through too many areas in succession, the bird will move again. This makes it impossible to catch up with the bird if it moves to a cross-map area, so you’ll need to fly to a different city and wait for the bird to move again.
Quick Ball - Use one of these at the beginning of the fight. Quick Balls have a 5x chance of catching a Pokémon when used as the first move in a fight, after which point they drop to a 1x chance. Dusk Ball - Best used for most of the catch phase. Dusk Balls have a 3. 5x chance of catching a Pokémon that’s in a cave, which applies to Sea Spirit’s Den. Timer Ball - Best used after your 31st turn, as the Timer Ball has a 4x chance of catching Pokémon after this point. Master Ball - While the Master Ball should be used for Mewtwo, you can use the Master Ball on Articuno/Zapdos/Moltres to guarantee a capture.
You can initiate the “Surf” action by approaching a body of water.
This is why it’s important to save before you enter Sea Spirit’s Den, as the fight may be triggered immediately after you enter the cave.
Your chances of catching the bird increase as the bird’s health decreases. If you accidentally defeat the bird, you’ll need to reload your save and try again.
After you’ve had 31 turns, start using Timer Balls, as the extra . 5x chance of catching a Pokémon will often give you the edge that you need. If you run out of PokéBalls before you can catch the bird, you’ll need to reload your save and try again.
Many of your lower-level Pokémon will level up after your catch the legendary bird.