Kiyomaro, First to Stand

Kiyomaro's power and toughness are each equal to the number of cards in your hand.
As long as you have four or more cards in hand, Kiyomaro has vigilance.
Whenever Kiyomaro deals damage, if you have seven or more cards in hand, you gain 7 life.

Decanter of Endless Water

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

Thought Vessel

You have no maximum hand size.
{T}: Add {C}.

Canopy Vista

({T}: Add {G} or {W}.)
This land enters tapped unless you control two or more basic lands.

Sergeant John Benton

Trample, haste
Share Intelligence — Whenever Sergeant John Benton deals combat damage to a player, you and that player each draw that many cards.

Arcane Signet

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

Sol Ring

Shield of the Oversoul

Enchant creature
As long as enchanted creature is green, it gets +1/+1 and has indestructible. (Damage and effects that say "destroy" don't destroy it. If its toughness is 0 or less, it's still put into its owner's graveyard.)
As long as enchanted creature is white, it gets +1/+1 and has flying.

Reliquary Tower

Psychosis Crawler

Psychosis Crawler's power and toughness are each equal to the number of cards in your hand.
Whenever you draw a card, each opponent loses 1 life.

Spellbook

Wing It

Target creature gets +2/+2 until end of turn. Put a flying counter on it. Scry 1.

Blossoming Defense

Target creature you control gets +2/+2 and gains hexproof until end of turn.

Spontaneous Flight

Target creature gets +2/+2 until end of turn. Put a flying counter on it.

Flaming Fist

Commander creatures you own have "Whenever this creature attacks, it gains double strike until end of turn."

Almost Perfect

Enchant creature
Enchanted creature has base power and toughness 9/10 and has indestructible.

Bastion Protector

Commander creatures you control get +2/+2 and have indestructible.

Enter the Unknown

Target creature you control explores. (Reveal the top card of your library. Put that card into your hand if it's a land. Otherwise, put a +1/+1 counter on the creature, then put the card back or put it into your graveyard.)
You may play an additional land this turn.

Call a Surprise Witness

Return target creature card with mana value 3 or less from your graveyard to the battlefield. Put a flying counter on it. It's a Spirit in addition to its other types.