Arcum Dagsson

{T}: Target artifact creature's controller sacrifices it. That player may search their library for a noncreature artifact card, put it onto the battlefield, then shuffle.

Sparring Construct

When Sparring Construct dies, put a +1/+1 counter on target creature you control.

Thrumming Stone

Spells you cast have ripple 4. (Whenever you cast a spell, you may reveal the top four cards of your library. You may cast spells with the same name as that spell from among the revealed cards without paying their mana costs. Put the rest on the bottom of your library.)

Persistent Petitioners

{1}, {T}: Target player mills a card. (They put the top card of their library into their graveyard.)
Tap four untapped Advisors you control: Target player mills twelve cards.
A deck can have any number of cards named Persistent Petitioners.

Aetherflux Reservoir

Whenever you cast a spell, you gain 1 life for each spell you've cast this turn.
Pay 50 life: Aetherflux Reservoir deals 50 damage to any target.

Lightning-Core Excavator

{5}, {T}, Sacrifice Lightning-Core Excavator: It deals 3 damage to any target.

Island

Cogwork Wrestler

Flash
When Cogwork Wrestler enters, target creature an opponent controls gets -2/-0 until end of turn.