One of the keys to winning a Pokmon Pocket battle is for players to get as many cards into their hands as possible as quickly as possible
This could be a big play to keep any fully evolved cards off the Bench and allow you to prevent a retreat into something much stronger
//// Ragnarok, Divine Deliverance Legendary Creature Beast Avatar 7/6 Vigilance, menace, trample, reach, haste When Ragnarok dies, destroy target permanent and return target nonlegendary permanent card from your graveyard to the battlefield
Similar to Greninja, it is also done in a more traditional art style
Take note, trainers
That said, I still feel Curse of Vitality is overall a weak card that won't see much play, but it still is a decent inclusion in Lifegain decks that can take advantage of the trigger, such as Oloro, Ageless Ascetic, Karlov of the Ghost Council, and many more