Since Rainbow Rare cards are no longer being printed, you should focus your search on card sets released between the Sun and Moon series, released in 2017, and the Scarlet and Violet series, released in 2022
As promised I'm also here with some new and improved (?) designs, since I plan to put an MPCfill order in early next week
You can only tap it for mana while removing component counters, but once the deck gets going, this card is more of an excuse to roll a d20 than a mana source
Each one either buffs a Creature or gives you an extra bonus for attacking
Once made there is usually a mad panic to find a way of dealing with him, if that fails you then start to lose tempo and card advantage as well as being highly restricted in what plays you can make
Fighting decks (unfavorable) represent ~10%