Summoning Pokémon

Summoning Pokémon is a late game PMU mechanic used to temporarily obtain Legendary or Mythical Pokémon for the duration of a dungeon. Summoning is a special form of Pokémon obtainment and is not considered as Pokémon recruitment.

Heart Slates
Heart Slates are dropped by their respective Pokémon and can only be used when combined with a Mystery Part. The rarity is influenced by the difficulty of the dungeons that their respective Pokémon appears in. For instance Pokémon in harder or longer dungeons typically have a higher drop chance, while Pokémon in easier or shorter dungeons have a lower drop chance. Due to the fact most Heart Slates are only dropped by dungeon bosses, they often hold great value to players. While only one of each specific Heart Slate can be combined per Mystery Part, they can also be dropped and subsequently traded. This feature is important as due to both the rarity and difficulty of attainment they are often worth a great amount of Poké on the player market.

Mystery Part
To use a Mystery Part it must be combined with at least one Heart Slate. Mystery Parts can only be obtained from Tanren Chambers (Normal path ending).

Combining
In the Southeastern Village in Archford, accessible after defeating Boggy Wastes, there is an Alakazam named Merlin that combines Heart Slate's with Mystery Part's. Merlin resides specifically in the Wisdom Hub on a hill on the eastern side of the Village.

The requirements for Mystery Part and Heart Slate combining are:
 * A Mystery Part, obtained from Tanren Chambers (Normal Path Ending).
 * A Heart Slate
 * Master Rank or above (13,500+ Explorer Points)
 * 100,000 Poké, increasing with every slate combination.

The cost for combining a Heart Slate with a Mystery Part can be determined with the formula:

$$(n + 1) * 100,000 Poké$$

With "n" being equal to the number of Heart Slates already fused with the respective Mystery Part. For example, the formula for a fourth mystery part combination would be:

$$(3 + 1) * 100,000 = 400,000 Poké$$

Summoning
To summon a Pokémon with a combined Mystery Part, bring the Mystery Part into a dungeon and have an empty slot in your team. Using the Mystery Part gives the user a list of the Legendary and Mythical Pokémon they fused the Heart Slates of and can use. Selecting any of the Pokémon listed summons the desired Pokémon with a level equal to that of the highest in the team. The summoned Pokémon will have one specific guaranteed move with the rest of its move being randomized from what it can learn through level up. It is also possible to teach the summoned Pokémon moves through the use of TMs, however any learnt moves will not persist through to subsequent summons.

Upon summoning the desired Pokémon, the Mystery Part will automatically be sent back to the users storage, the music will change to "PSMD) Second Dark Matter Battle", and the player will get a dialogue box saying "Merlin's words echoed: 'The Mystery Part will be sent back to the storage upon summoning a Guardian.' ". A summoned Pokémon will leave the player's team once the user leaves the dungeon.

Tips

 * You can save millions of Poké in combining costs by having multiple Mystery Parts.