Melemele Grand Trial

Walkthrough: After completing Captain Ilima's Trial, helping Little in Melemele Meadow, and battling Hau on Route 3, once you return back to Iki Town, you can challenge Kahuna Hala to your Grand Trial. He is a Master of Fighting Type Pokemon.

Kahuna Hala - Level 14 Mankey, Level 14 Makuhita, Level 15 Crabrawler w/Fightinium Z.

After defeating Hala, you will receive your next Passport Stamp that will allow any Pokemon up to Level 35 to obey your instructions. Kahuna Hala will even give you the Fightinium Z-Crystal, as well as the Rider Pager with the ability to call on Tauros to ride upon.

Professor Kukui will then offer to take you to the next Island of Alola so you can continue your Island Challenge, on his boat in the Hau'oli Marina. Hau and Lille will travel with the two of you as well to Akala Island. However, before leaving, a player can first finally explore Ten Carat Hill or challenge Captain Ilima to another Battle by first talking with him in his home in Hau'oli City.