If a Set Booster pack has such a card, it can be of any rarity
The video has an explanation of our thought process in designing this product and how it looks when stacked
From what I know, there are over 160 different English/Japanese cards for Latios and Latias combined
The player pays 2000 Life Points to activate it, then counts each turn that passes, starting with the turn when Final Countdown was activated as the first one
This is a bit less efficient, but the effect is actually not noticeable: each Mimic Vat activation will create a number of usable damage triggers "for each Clash of Realities", instead of "for each Clash of Realities TIMES Doubling Season", since all the triggers for the copies are put on the stack at the same time with no opportunity to act in between to increase the number of triggers that might be created
Evolve Darkrai V to use Darkrai VSTAR's Dark Pulse attack, which grows in strength for each Darkness Energy attached to all of your Pokmon