Copycat is used in most decks, while Mega Absol ex and Hydreigon are relevant competitive Pokemon
Peak seasons may add a few days
According to the rules the process of casting creature cards (or any other non-land cards) consists of the following stages: you put a creature card on the stack, define its total casting cost and it locks in, then you get a chance to activate mana abilities (but only if the total cost requires mana), and, finally, you pay the cost
Other cards like Dedenne, Morelull, and Snivy mean well possibly see new metas emerge to knock those pesky Misty/Articuno decks down a peg or two
It must be small enough to be practical
And you may do this any number of times