bloomburrow collector booster box case - Play a party will strike out to investigate what has befallen a neighboring town Bloomburrow - Collector Booster Pack

Pokemon GO set has been added with 7 new cards, including 2 new promos

Xira, the Golden Sting and Vazi, Keen Negotiator break out of this mold, but they strike me as more lieutenant-types, not arc villains by themselves

C Common Rainbow Refraction X SPELL Quick-Play If a monster(s) you control whose original name is "Rainbow Dragon" or "Rainbow Dark Dragon" activated its effect this turn: Special Summon any number of "Crystal Beast" monsters with different names from your Deck

I would actually argue that Armada Wurm is the more proactive of the two and that Centaur Healer is more of a sideboard card (though it depends substantially on the tenor of the metagame)