msem-instigator

Indestructible
As long as your devotion to blue is less than five, Thassa isn't a creature.
At the beginning of each combat, you may tap or untap another target nonland permanent.
{2}{U}: Create a 1/1 blue Merfolk Rogue creature token with “{T}: Draw a card, then discard a card.”

Enchant creature you control
When Thassa's Benefaction enters, scry 2.
Enchanted creature gets +1/+0 and has flying.

Heroic — Whenever you cast a spell that targets Thassa's Shoreguards, tap target creature an opponent controls. It doesn't untap during its controller's next untap step.
Whenever Thassa's Shoreguards deals combat damage to a player, draw a card.

{5}{U}{U}: Thassa's Tidebringer can't be blocked this turn. This ability costs {1} less to activate for each creature you control with a counter on it.

This spell costs {2} more to cast for each target beyond the first.
Choose one or more —
• Counter target creature or planeswalker spell with mana value 4 or less.
• Exile target permanent you control, then return that card to the battlefield under your control.
• Target player draws two cards, then discards two cards and mills two cards.

Choose one —
• Draw three cards, then discard a card.
• The owner of target nonland permanent puts it on the top or bottom of their library.

Colossal 2—{6}{U} (You may cast this for its colossal cost to have it enter with two +1/+1 counters; or pay {6}{U} as a sorcery: Put two +1/+1 counters on it if it has none.)
When Titanic Fathomclaw's colossal ability puts one or more counters on it, return target instant or sorcery card from your graveyard to your hand.

If you've scried this turn, this spell costs {2} less to cast and can't be countered.
Draw two cards.

Return target nonland permanent to its owner's hand. Scry 1.

All creatures get -4/-4 until end of turn. If a creature would die this turn, exile it instead.

When Asphodel Gravedealer dies, choose one —
• Put a +1/+1 counter on target creature you control.
• Create a Treasure token. (It's an artifact with “{T}, Sacrifice this artifact: Add one mana of any color.”)

Deathtouch
Chronicle (As this enters and after your draw step, add a lore counter. Stop after III.)
[Lore I-II] You may sacrifice another creature. If you do, draw a card.
[Lore III] Remove all lore counters from Astral Leech. Each opponent sacrifices a creature.

Return all creature and planeswalker cards from your graveyard to the battlefield.

Flying, haste
{2}{B}: Devourer of Dread gets +1/+1 until end of turn. If there are three or more creature cards in your graveyard, put a +1/+1 counter on Devourer of Dread instead.

All creatures get -2/-2 until end of turn. Scry 1.

This spell costs {2} more to cast for each target beyond the first.
Choose one or more —
• Target non-Gorgon creature gets -2/-2 until end of turn. Remove all counters from it.
• Return target creature or planeswalker card from your graveyard to your hand. You gain 4 life.
• Exile target player's graveyard.

Indestructible
As long as your devotion to black is less than five, Erebos isn't a creature.
Other creatures you control dying causes abilities of that creature to trigger as though it entered.
{2}{B}: Each opponent loses 1 life. You gain life equal to the life lost this way.

Enchant creature you control
When Erebos's Benefaction enters, scry 2.
Enchanted creature gets +2/+2 and has menace.

Whenever Erebos's Whipslang or another enchantment you control enters, each opponent loses 1 life and you gain 1 life.

Choose one —
• Target opponent reveals their hand. You may choose a creature, enchantment, or planeswalker card from it. That player discards that card.
• Target opponent sacrifices an enchantment.

When Felhide Marauder enters, if you control a creature with power greater than its base power, Felhide Marauder gains haste until end of turn.

Return up to two target creature cards from your graveyard to your hand. If you control a creature with power greater than its base power, you gain 3 life.

Flash
Flying
{2}{B}, Exile three cards from your graveyard: Create a tapped 2/2 black Zombie creature token.

Destroy target non-Gorgon creature. Scry 1.

Flying, trample
When Greedstoker Demon enters, you lose X life and create X Treasure tokens, where X is your devotion to black. (Each {B} in the mana costs of permanents you control counts toward your devotion to black.)
You can't sacrifice more than one Treasure each turn.