Howling Mine

At the beginning of each player's draw step, if Howling Mine is untapped, that player draws an additional card.

Kami of the Crescent Moon

At the beginning of each player's draw step, that player draws an additional card.

Dictate of Kruphix

Flash (You may cast this spell any time you could cast an instant.)
At the beginning of each player's draw step, that player draws an additional card.

Command Tower

{T}: Add one mana of any color in your commander's color identity.

Counterspell

Decanter of Endless Water

You have no maximum hand size.
{T}: Add one mana of any color.

Force of Will

You may pay 1 life and exile a blue card from your hand rather than pay this spell's mana cost.
Counter target spell.