Omniscience

You may cast spells from your hand without paying their mana costs.

Seedborn Muse

Untap all permanents you control during each other player's untap step.

Vedalken Orrery

You may cast spells as though they had flash.

Kruphix, God of Horizons

Indestructible
As long as your devotion to green and blue is less than seven, Kruphix isn't a creature.
You have no maximum hand size.
If you would lose unspent mana, that mana becomes colorless instead.

Keiga, the Tide Star

Flying
When Keiga, the Tide Star dies, gain control of target creature.