Mightyena found Milo and Riley in thunderwave cavern as she offered them help as she took them to a den of other mightyenas hanging out in some sort of thunder evolution stone cavern where the electric types for some reason are scared to go near it.  Mightyena finds Sara as she gives Milo a Pecha berry to cure his poison.

Mightyena's personality  she is very honest and open minded when she talks to Milo and Riley about their team effort