Have

Yahenni, Undying Partisan

Haste
Whenever a creature an opponent controls dies, put a +1/+1 counter on Yahenni, Undying Partisan.
Sacrifice another creature: Yahenni gains indestructible until end of turn.

Swamp

Servo Schematic

When Servo Schematic enters or is put into a graveyard from the battlefield, create a 1/1 colorless Servo artifact creature token.

Animation Module

Whenever one or more +1/+1 counters are put on a permanent you control, you may pay {1}. If you do, create a 1/1 colorless Servo artifact creature token.
{3}, {T}: Choose a counter on target permanent or player. Give that permanent or player another counter of that kind.

Fatal Push

Destroy target creature if it has mana value 2 or less.
Revolt — Destroy that creature if it has mana value 4 or less instead if a permanent you controlled left the battlefield this turn.

Weaponcraft Enthusiast

Fabricate 2 (When this creature enters, put two +1/+1 counters on it or create two 1/1 colorless Servo artifact creature tokens.)

Metallic Mimic

As Metallic Mimic enters, choose a creature type.
Metallic Mimic is the chosen type in addition to its other types.
Each other creature you control of the chosen type enters with an additional +1/+1 counter on it.

Aetherborn Marauder

Flying, lifelink
When Aetherborn Marauder enters, move any number of +1/+1 counters from other permanents you control onto Aetherborn Marauder.

Yahenni's Expertise

All creatures get -3/-3 until end of turn.
You may cast a spell with mana value 3 or less from your hand without paying its mana cost.

Syndicate Trafficker

{1}, Sacrifice an artifact: Put a +1/+1 counter on Syndicate Trafficker. It gains indestructible until end of turn.

Midnight Entourage

Other Aetherborn you control get +1/+1.
Whenever Midnight Entourage or another Aetherborn you control dies, you draw a card and you lose 1 life.

Gifted Aetherborn

Tragic Slip

Target creature gets -1/-1 until end of turn.
Morbid — That creature gets -13/-13 until end of turn instead if a creature died this turn.