Ok can someone who has used this guy explain his ultimate ability. It doesn't change hand size so at the end turn you would discard down with {jace memory adept}. Thanks.
After presumably milling your opponent down a whole bunch already in a Jace-centric deck[ {Jace's Erasure}, {Jace's Archivist}, {Thought scour}], he'll be at or below 20 cards in his library, at which point you force him to draw 20, and when he can't he loses the game.
Or you draw 20 and keep your perfect hand.
Any player may draw 20 cards that controller of jace wants too. At the end of turn you would have to discard down to 7 cards unless you have a card in play that states you have no maximum hand size like {venser's journal}
Thanks guys.