Sol Ring

Thought Vessel

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

Krenko, Mob Boss

{T}: Create X 1/1 red Goblin creature tokens, where X is the number of Goblins you control.

Mountain

Soul's Attendant

Whenever another creature enters, you may gain 1 life.

Command Tower

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

Myrel, Shield of Argive

During your turn, your opponents can't cast spells or activate abilities of artifacts, creatures, or enchantments.
Whenever Myrel attacks, create X 1/1 colorless Soldier artifact creature tokens, where X is the number of Soldiers you control.

Roaming Throne

Ward {2}
As this creature enters, choose a creature type.
This creature is the chosen type in addition to its other types.
If a triggered ability of another creature you control of the chosen type triggers, it triggers an additional time.

Ocelot Pride

First strike, lifelink
Ascend (If you control ten or more permanents, you get the city's blessing for the rest of the game.)
At the beginning of your end step, if you gained life this turn, create a 1/1 white Cat creature token. Then if you have the city's blessing, for each token you control that entered this turn, create a token that's a copy of it.

Arabella, Abandoned Doll

Whenever Arabella attacks, it deals X damage to each opponent and you gain X life, where X is the number of creatures you control with power 2 or less.

Arcane Signet

Darien, King of Kjeldor

Whenever you're dealt damage, you may create that many 1/1 white Soldier creature tokens.

Guide of Souls

Whenever another creature you control enters, you gain 1 life and get {E} (an energy counter).
Whenever you attack, you may pay {E}{E}{E}. When you do, put two +1/+1 counters and a flying counter on target attacking creature. It becomes an Angel in addition to its other types.

Ajani's Welcome

Whenever a creature you control enters, you gain 1 life.

Reliquary Tower

Soul Warden

Whenever another creature enters, you gain 1 life.

Decanter of Endless Water

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

Plains

Panharmonicon

If an artifact or creature entering causes a triggered ability of a permanent you control to trigger, that ability triggers an additional time.

Helm of the Host

At the beginning of combat on your turn, create a token that's a copy of equipped creature, except the token isn't legendary. That token gains haste.
Equip {5}

Authority of the Consuls

Creatures your opponents control enter tapped.
Whenever a creature an opponent controls enters, you gain 1 life.