Myne, Bookworm

You have no maximum hand size.

At the beginning of each players upkeep, if another player has more cards in hand than them, they may draw cards equal to the difference. When they do, put a number of +1/+1 counters onto target creature equal to the amount of cards drawn this way.

At the beginning of your end step, draw a card for each effect you control that alters your maximum hand size.