Amphibious Kavu

Whenever this creature blocks or becomes blocked by one or more blue and/or black creatures, this creature gets +3/+3 until end of turn.

Lure

Enchant creature
All creatures able to block enchanted creature do so.

Ezuri, Stalker of Spheres

When Ezuri enters, you may pay {3}. If you do, proliferate twice.
Whenever you proliferate, draw a card.

Queza, Augur of Agonies

Whenever you draw a card, target opponent loses 1 life and you gain 1 life.

Siege Behemoth

Hexproof
As long as this creature is attacking, for each creature you control, you may have that creature assign its combat damage as though it weren't blocked.

Denry Klin, Editor in Chief

Denry Klin enters with your choice of a +1/+1, first strike, or vigilance counter on it.
Whenever a nontoken creature you control enters, if Denry Klin has counters on it, put the same number of each kind of counter on that creature.

Chameleon Spirit

As this creature enters, choose a color.
Chameleon Spirit's power and toughness are each equal to the number of permanents of the chosen color your opponents control.

Watcher of the Spheres

Flying
Creature spells with flying you cast cost {1} less to cast.
Whenever another creature you control with flying enters, this creature gets +1/+1 until end of turn.

Y'shtola Rhul

At the beginning of your end step, exile target creature you control, then return it to the battlefield under its owner's control. Then if it's the first end step of the turn, there is an additional end step after this step.

Minn, Wily Illusionist

Whenever you draw your second card each turn, create a 1/1 blue Illusion creature token with "This token gets +1/+0 for each other Illusion you control."
Whenever an Illusion you control dies, you may put a permanent card with mana value less than or equal to that creature's power from your hand onto the battlefield.