Aria Thane, Mental Prodigy

You have no maximum hand size.
Whenever you discard a card, you may return
it from your graveyard to the top of your library.
Whenever you cast a spell without paying its
mana cost, you may choose to resolve it as though
you had paid an alternate cost for it by paying
that cost. If the spell has {x} in any of its costs,
pay {x} as you cast it to determine the value of X.