In Pokemon Sun And Moon, in order to unlock the Eevium Z and Eevee Z crystal, first you need to battle and defeat elite four in the storyline. Then you need to reach the Battle Royal Avenue to take on the quest in order to get the Eevium Z and Eevee Z crystal. The following guide shows how to get Eevium Z and Eevee Z crystal in the game.
How to get Eevium Z and Eevee Z Crystal:
In order to get the Eevium Z and Eevee Z crystal, you need to head for the Battle Royal Avenue with Charizard glide. After reaching there, go to the She Store and there you will get some discount. Then go to the first Cashier in the store and talk to him to get the quest.
The quest is about defeating 8 trainers and the cashier will even give you the location of those people. You need to go to them and defeat all of them. Once you are done with them come back to the Store and talk to the Cashier, the Cashier will request to battle with you.
Once you defeat him, he will give the Eevium Z and Evee Z crystal. Evee Z crystal can be used to unlock the special Evee Z ability for Eevee.
Check out our Pokemon Sun and Pokemon Moon Wiki page for more guides and features on the game.