msem-instigator

Flash
Ocean's Edge Kraken enters with a hexproof counter on it.
{6}{U}{U}, Remove a hexproof counter from Ocean's Edge Kraken: Return all other creatures to their owners' hands.

Exile up to two target creatures controlled by different players. Return those creatures to the battlefield under their owners' control at the beginning of the next end step.

Each player sacrifices a creature. If a player lost 3 or more life this turn, each opponent sacrifices a creature instead.

Trample, haste
When Oil Driller enters, salvage two cards at random. (Exile those cards from your graveyard until this creature leaves the battlefield. Whenever this creature deals combat damage to a player, put a card it salvaged into your hand.)
At the beginning of your end step, sacrifice Oil Driller.

Other Merfolk you control get +1/+1.
When Olantin Pearlreader enters, scry 2. Then draw a card if you control two or more other Merfolk.

Target creature gets -X/-X until end of turn, where X is the number of enchantments you control.

Oldgrove Nurturer enters with a +1/+1 counter on it.
{G}, Remove a +1/+1 counter from a creature you control: Create a 1/1 colorless Construct artifact creature token.

Whenever you attack with one or more Pirates, create that many 1/1 white Bird creature tokens with flying that are tapped and attacking. At end of combat, choose one of those tokens, then exile the rest.

When Olten Surveyor enters, choose any number. Each opponent creates a 1/1 colorless Servo artifact creature token for each mode chosen.
• Destroy target artifact or enchantment with mana value 3 or less.
• Shuffle up to four cards from target player's graveyard into their library.
• You gain 4 life.

Trample
Ward {3} (Whenever this creature becomes the target of a spell or ability an opponent controls, counter it unless that player pays {3}.)
Cycling {2} ({2}, Discard this card: Draw a card.)

Look at the top two cards of your library. Put one of them into your hand and the rest into your graveyard.
Rerun (If you cast this from your hand, exile it as it resolves. Whenever a creature you control dies, you may cast this card from exile without paying its mana cost.)

Ominous Dragoncaller gets +1/+1 and has flying as long as you control a Dragon.

This spell costs {1} less to cast for each card in your graveyard.
Menace

This spell costs {G} less to cast if it targets a blue or black permanent.
Destroy target artifact, enchantment, or planeswalker.

This spell costs {1}{B} less to cast if it targets a green or white permanent.
Destroy target creature or planeswalker.

This spell costs {1}{U} less to cast if it targets a red or green spell.
Counter target spell.
Draw a card.

Return target creature card with mana value 3 or less from your graveyard to the battlefield. If its mana value is less than 3, you gain life equal to the difference.

This spell costs {R} less to cast if it targets a white or blue permanent.
Once Scarred deals 4 damage to target creature or planeswalker.

This spell costs {W} less to cast if it targets a black or red permanent.
Exile target nonland permanent with mana value 3 or less.

For each player, choose a creature or planeswalker that player controls. Each player sacrifices all creatures and planeswalkers they control not chosen this way.
Fuse (You may cast one or both halves of this card from your hand.)

Destroy target monocolored creature.
Augmented — If you've spent {W}{U}{B}{R}{G} to cast spells this turn, return that card to the battlefield under your control.

Search your library for a basic land card, reveal it, put it into your hand, then shuffle. Scry 2.

If you would germinate, instead create a 1/1 green Saproling creature token, then put a +1/+1 counter on a creature you control.
{2}{W}{W}: Germinate. (Put a +1/+1 counter on a creature or create a 1/1 green Saproling creature token.)

Archive 6 (As this enters, shuffle the top six cards of your main library into a new face up library. Sacrifice this after the archived library is empty.)
Whenever a creature or planeswalker you control dies, you may play a card from the archived library. (You still pay its costs.)

Flying
Spells your opponents cast cost an additional 2 life to cast.