Riven, The Wish Dragon

Whenever you create a dragon tokens, create that many +1
Whenever a non-dragon token is created, its creator may pay {1}. If they don't, it gets a -1/-1 counter.
WISH {t}{1}{w}{u}{b}{r}{g}: Exile your hand, then draw 7 cards. Cards exiled this way return to the top of your library in any order after 3 turns. Everyone has no max hand size.