Once your end step begins, it's too late to put a counter on Wakka in order to cause this ability to trigger
It's at $29.50 market and not much lower elsewhere
Then exile it.) "Flashback [cost]" means "You may cast this card from your graveyard if the resulting spell is an instant or sorcery spell by paying [cost] rather than paying its mana cost" and "If the flashback cost was paid, exile this card instead of putting it anywhere else any time it would leave the stack." You must still follow any timing restrictions and permissions, including those based on the card's type
4 through a soft launch at local game stores showcasing Starter Deck events
The Legend rule may kill your tokens, but it wont stop them from taking opposing text boxes with them
Theres also the possibly battlefield-shaking Beyond the Horizon, which costs 7 and, in the right instance, can really shift the game to your advantage