Skrelv, Defector Mite

Toxic 1 (Players dealt combat damage by this creature also get a poison counter.)
Skrelv can't block.
{W/P}, {T}: Choose a color. Another target creature you control gains toxic 1 and hexproof from that color until end of turn. It can't be blocked by creatures of that color this turn. ({W/P} can be paid with either {W} or 2 life.)

Revel in Silence

Your opponents can't cast spells or activate planeswalkers' loyalty abilities this turn.
Exile Revel in Silence.

Flamescroll Celebrant

Whenever an opponent activates an ability that isn't a mana ability, this creature deals 1 damage to that player.
{1}{R}: This creature gets +2/+0 until end of turn.

Flamescroll Celebrant // Revel in Silence

Doorkeeper Thrull

Flash
Flying
Artifacts and creatures entering don't cause abilities to trigger.

Guardian of the Great Door

As an additional cost to cast this spell, tap four untapped artifacts, creatures, and/or lands you control.
Flying

Dauntless Bodyguard

As this creature enters, choose another creature you control.
Sacrifice this creature: The chosen creature gains indestructible until end of turn.

Containment Priest

Flash
If a nontoken creature would enter and it wasn't cast, exile it instead.

Thalia, Guardian of Thraben

First strike
Noncreature spells cost {1} more to cast.

Dusk Legion Duelist

Vigilance
Whenever one or more +1/+1 counters are put on this creature, draw a card. This ability triggers only once each turn.

Anafenza, Kin-Tree Spirit

Whenever another nontoken creature you control enters, bolster 1. (Choose a creature with the least toughness among creatures you control and put a +1/+1 counter on it.)