Zaltuhn, Timeshift Spellcaster

Other Wizards you control get +1/+1
At the end of every turn, if you dealt damage to
a player, each player exiles the top card of
their library. The player who exiled the card
with the highest mana value takes an extra
turn after this one. If two or more players'
cards are tied for highest, the tied players
repeat this process until the tie is broken.
"Nifty little gadget..."