The Ozolith

Whenever a creature you control leaves the battlefield, if it had counters on it, put those counters on The Ozolith.
At the beginning of combat on your turn, if The Ozolith has counters on it, you may move all counters from The Ozolith onto target creature.

Spara's Headquarters

({T}: Add {G}, {W}, or {U}.)
Spara's Headquarters enters the battlefield tapped.
Cycling {3} ({3}, Discard this card: Draw a card.)

Drannith Ruins

{T}: Add {C}.
{2}, {T}: Put two +1/+1 counters on target non-Human creature that entered the battlefield this turn.

Forgotten Ancient

Whenever a player casts a spell, you may put a +1/+1 counter on Forgotten Ancient.
At the beginning of your upkeep, you may move any number of +1/+1 counters from Forgotten Ancient onto other creatures.

Depopulate

Each player who controls a multicolored creature draws a card. Then destroy all creatures.

Wingshield Agent

Wingshield Agent enters the battlefield with a shield counter on it. (If it would be dealt damage or destroyed, remove a shield counter from it instead.)
Whenever Wingshield Agent attacks, up to one other target creature gains flying until end of turn.

Falco Spara, Pactweaver

Flying, trample
Falco Spara, Pactweaver enters the battlefield with a shield counter on it.
You may look at the top card of your library any time.
You may cast spells from the top of your library by removing a counter from a creature you control in addition to paying their other costs.

Gala Greeters

Alliance — Whenever another creature enters the battlefield under your control, choose one that hasn't been chosen this turn —
• Put a +1/+1 counter on Gala Greeters.
• Create a tapped Treasure token.
• You gain 2 life.