As the player attempts to leave, Mr. Luck lets the player know that they are contractually obligated to bring him more Black Prisms in the future, and offers to give the player other contracts and items in return.

For the A-Gang contracts, they change your character model to their respective character, except for Ana, she won't work. I dunno if there are consequences beyond that though.

There is a 1% chance for the Technique, Shiny, and Wealth contracts to have an altered effect. Technique will give all Pokemon Self-Destruct for 20 encounters.

What happens when you sign the contract? I really don't trust him.

Mr. Luck's tent is a Red and White circus style tent found throughout the Aevium region. On the outside it has a striped red and white tarp held down by 6 wooden stakes, 4 of which are visible to the player.

Yep. But you do have to give up the 999 black prisms to Mr. Luck so it's honestly not worth grinding for. Save the prisms for the contracts and stuff you want to buy.

He'll offer all sorts of things in trade for the prisms, including contracts that can help you in all sorts of ways! He can increase the odds of running into shinies, make it so that there's a chance that wild Pokémon have egg moves by default, increase the amount of money earned in battle...

The spirit battles with Keta, Jenner, and Xara/Jean respawn every day and they all give black prisms as a reward for winning. If you're lucky, you might be able to find one in the Kecleon shop on...

Completing this quest rewards the player with access to Mr. Luck's Black Prism shop. Enter Luck's Tent in Gearen Park, talk to Mr. Luck, and have your appearance changed. Talk to Mr. Luck again and ask him to change you back. Head into the room on the right, talk to him again, and accept his new contract.

Upon approaching, an Aevian Jangmo-o will run off towards Luck's Tent. Enter Luck's Tent in the desert. After signing the contract, you will need 13 Black Prisms to purchase this Pokémon. Once you have them, speak to Doxine to purchase the Aevian Jangmo-o. Aevian Jangmo-o can be traded for Jangmo-o at a house at the south end of Zorrialyn Desert.