plasma blast booster box B&W Pokémon Pack EX takes the battlefield Pokémon TCG: Black & White:

Then to Diamond and Pearl and the consolidation, at the time, of the Expanded format, now from Black/White era onward, with our emotional memory and also the memory of Expanded format decks which can wreak havoc with combos, or that play with the help of a very different deckbuilding

The sole exception being Spectre, as for him, time started moving when the Project happened

O-Ring effects dont typically have much room for payoffs through other cards, and if you're going for benefiting from enters the battlefield or leaves the battlefield effects, you should probably check out blink/flicker effects

There are some metagame cards that use tokens, like Gorz the emissary of darkness or Dandylion, but i doubt you want to use those tokens for a card like this