Mindshrieker

Flying
{2}: Target player mills a card. Mindshrieker gets +X/+X until end of turn, where X is the milled card's mana value.

Hangarback Walker

Hangarback Walker enters with X +1/+1 counters on it.
When Hangarback Walker dies, create a 1/1 colorless Thopter artifact creature token with flying for each +1/+1 counter on Hangarback Walker.
{1}, {T}: Put a +1/+1 counter on Hangarback Walker.

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.

Loyal Inventor

Vigilance
When Loyal Inventor enters, you may search your library for an artifact card, reveal it, then shuffle. Put that card into your hand if you control an Assassin. Otherwise, put that card on top of your library.

Karn, Legacy Reforged

Karn, Legacy Reforged's power and toughness are each equal to the greatest mana value among artifacts you control.
At the beginning of your upkeep, add {C} for each artifact you control. This mana can't be spent to cast nonartifact spells. Until end of turn, you don't lose this mana as steps and phases end.

Sting, the Glinting Dagger

Equipped creature gets +1/+1 and has haste.
At the beginning of each combat, untap equipped creature.
Equipped creature has first strike as long as it's blocking or blocked by a Goblin or Orc.
Equip {2}

Spellskite

{U/P}: Change a target of target spell or ability to Spellskite. ({U/P} can be paid with either {U} or 2 life.)

Rocket Launcher

{2}: Rocket Launcher deals 1 damage to any target. Destroy Rocket Launcher at the beginning of the next end step. Activate only if you've controlled Rocket Launcher continuously since the beginning of your most recent turn.