Unless the ability has a printed limitation on it, you may use it as often as you like, provided you are able to pay the abilitys cost each time
You can imagine where if you topdeck a creature you cast it, give it haste, and attack with it
Thats the ethos behind this Oricorio and Tapu Koko deck, which lets you safely deal damage with Tapu Koko and, thanks to its Volt Switch attack, switch out to Oricorio for the next turn, negating all damage from opposing Pokmon ex cards
Older reverse holo cards or those featuring popular Pokmon are particularly valuable
The Tribe-Infecting and Tribe-Shocking Virus cards were not used since they have "Tribe" in their name as part of an archetype
He can show up, steal a big creature , and use it to win the game, or he can just be the last part of a mana combo that causes everyone else to lose infinite life