msem-instigator

Enchant creature
Enchanted creature can't attack or block unless its controller pays {3}.
Activated abilities of enchanted creature cost {3} more to activate.

Whenever Oracle of Flames becomes tapped, up to one target creature you control gets +2/-2 until end of turn.

Whenever Ore Tunneler deals damage to an opponent, tap target land they control. It doesn't untap during its controller's next untap step.

Whenever Orria Mirrorpelt becomes the target of a spell, exile that spell. If Orria Mirrorpelt was its only target, copy it for each other creature target player controls. Each copy targets a different one of those creatures.

Primal {1}{G}{G} (During your turn, you may cast this spell for {1}{G}{G} instead of playing a land.)
When Orria's Ward enters, if you played a land this turn, draw a card. Otherwise, put two +1/+1 counters on it.

Whenever you make first contact, Oscuran Wingmate gains flying until end of turn. (You make first contact the first time each turn you cast a spell with a name not in your graveyard or control already.)

Distorted (This creature can be blocked by tapped creatures but not untapped creatures.)

Distorted (This creature can be blocked by tapped creatures but not untapped creatures.)
Oslyd Heretic gets +1/+1 as long as you control no other creatures.

Enchant player
At the beginning of enchanted player's upkeep, they tap an untapped creature they control.

Enchant player
Whenever enchanted player becomes the target of a spell or ability they don't control, if it isn't a copy, its controller copies it.

Hexproof
When Overburdened Trader enters, create three 1/1 colorless Construct artifact creature tokens.

Counter target spell. For each other card named Overcharge in your graveyard, create a colorless Canister artifact token with “{T}, Sacrifice this artifact: Add {C}.”

Until end of turn, creatures you control have base power X/Y, where X is the greatest base power among creatures you control and Y is the greatest base toughness among creatures you control.
If you control a creature with flying, creatures you control gain flying until end of turn. The same is true for first strike, haste, lifelink, menace, prowess, trample, and vigilance.

Any number of target players each draw seven cards, then discard seven cards.

{G}, Tap an untapped Nymph you control: Overgrown Beast gets +2/+2 until end of turn.

{T}, Pay 1 life: Add {G} or {W}.
{1}, {T}, Sacrifice Overgrown Refuge: Investigate. (Create a colorless Clue artifact token with “{2}, Sacrifice this artifact: Draw a card.”)

Overgrown Siren must be blocked if able.

Trample
Overgrown Spellroot gets +1/+1 for each creature token you control.
When Overgrown Spellroot enters, create four 1/1 black Worm creature tokens.

Harness (You may tap a creature you control as you cast this spell. If you do, reduce this spell's mana cost by that creature's power.)
Overheat deals X damage to any target.

Overkill deals 4 damage to any target that was dealt damage this turn.

Choose target player, then choose two —
• That player loses 2 life.
• That player draws two cards.
• Put two -1/-1 counters on target creature that player controls.

Enchant creature
Enchanted creature can't block.
Whenever enchanted creature attacks an opponent, it gets +2/+2 until end of turn.

When Paint by Numbers enters, put up to ten brush counters on it.
Whenever a player casts a instant or sorcery spell with mana value equal to the number of brush counters on Paint by Numbers, remove a brush counter from it and copy that spell. You may choose new targets for the copy. Then sacrifice Paint by Numbers if it has no brush counters.

{1}, Discard a card: Painted Watcher gets +1/+1 and becomes the color of your choice until end of turn.

Palace of Tomorrows enters tapped.
{T}: Add {U}.
{2}{U}, {T}: Target player mills three cards.