Diviner's Portent

Roll a d20 and add the number of cards in your hand.
1—14 | Draw X cards.
15+ | Scry X, then draw X cards.

Rewind

Counter target spell. Untap up to four lands.

Rush of Blood

Target creature gets +X/+0 until end of turn, where X is its power.

Hall of Oracles

{T}: Add {C}.
{1}, {T}: Add one mana of any color.
{T}: Put a +1/+1 counter on target creature. Activate only as a sorcery and only if you've cast an instant or sorcery spell this turn.

Command Tower

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