This trick reminds me of the old TCG days. I never collected the cards, but I did have the game. You could use a pokemon with very high HP, like Chansey, combined with an ability like the Alakazam shown in the link. His ability lets you move damage counters around your team however you want. put all the damage on your pokemon with high HP and play the card scoop up. It lets you return the damaged pokemon to your hand, while in the process removing all the damage on them. It's an old trick, but still very effective. It'll work just as well with Reunilicus instead of Alakazam since it's the same ability.