Herald of Slaanesh

Locus of Slaanesh — Demon spells you cast cost {2} less to cast.
Other Demons you control have haste.

Purestrain Genestealer

Purestrain Genestealer enters the battlefield with two +1/+1 counters on it.
Vanguard Species — Whenever Purestrain Genestealer attacks, you may remove a +1/+1 counter from it. If you do, search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

Cogwork Assembler

{7}: Create a token that's a copy of target artifact. That token gains haste. Exile it at the beginning of the next end step.

Resolute Rider

{W/B}{W/B}: Resolute Rider gains lifelink until end of turn.
{W/B}{W/B}{W/B}: Resolute Rider gains indestructible until end of turn. (Damage and effects that say "destroy" don't destroy it.)

Displaced Dinosaurs

As a historic permanent enters the battlefield under your control, it becomes a 7/7 Dinosaur creature in addition to its other types. (Artifacts, legendaries, and Sagas are historic.)

Genestealer Locus

Neurotraumal Rod — Whenever a creature attacks you, it gets -1/-0 until end of turn.
Whenever a creature attacks one of your opponents, it gets +0/+1 until end of turn.

Grumgully, the Generous

Each other non-Human creature you control enters the battlefield with an additional +1/+1 counter on it.

Mistmeadow Witch

{2}{W}{U}: Exile target creature. Return that card to the battlefield under its owner's control at the beginning of the next end step.

Urbis Protector

When Urbis Protector enters the battlefield, create a 4/4 white Angel creature token with flying.

Sicarian Infiltrator

Flash
Squad {2} (As an additional cost to cast this spell, you may pay {2} any number of times. When this creature enters the battlefield, create that many tokens that are copies of it.)
Benediction of the Omnissiah — When Sicarian Infiltrator enters the battlefield, draw a card.

Bear's Companion

When Bear's Companion enters the battlefield, create a 4/4 green Bear creature token.

Painsmith

Whenever you cast an artifact spell, you may have target creature get +2/+0 and gain deathtouch until end of turn.

Trygon Prime

Subterranean Assault — Whenever Trygon Prime attacks, put a +1/+1 counter on it and a +1/+1 counter on up to one other target attacking creature. That creature can't be blocked this turn.

Archon of Absolution

Flying
Protection from white (This creature can't be blocked, targeted, dealt damage, enchanted, or equipped by anything white.)
Creatures can't attack you or planeswalkers you control unless their controller pays {1} for each of those creatures.