Target player sacrifices a creature of their choice.

Fathomless descent — All creatures get -X/-X until end of turn, where X is the number of permanent cards in your graveyard.

Increment (Whenever you cast a spell, if the amount of mana you spent is greater than this creature's power or toughness, put a +1/+1 counter on this creature.)
: Add an amount of equal to this creature's power.

As an additional cost to cast this spell, sacrifice an artifact or creature.
Draw two cards.

: Draw two cards.

(: Add .)

Flash (You may cast this spell any time you could cast an instant.)
Whenever this creature is dealt damage, draw that many cards.

The Space Family Goblinson has trample as long as you've rolled three or more dice this turn.
Whenever you roll a die, put a +1/+1 counter on The Space Family Goblinson.

At the beginning of your end step, two target players each reveal the top card of their library. They each lose life equal to the mana value of the card revealed by the other player. Then they each put the card they revealed into their hand.

Whenever this creature enters or attacks, put a +1/+1 counter on target creature you control with power 2 or less.

Demonstrate (When you cast this spell, you may copy it. If you do, choose an opponent to also copy it. Players may choose new targets for their copies.)
Create a token that's a copy of target permanent you control.

Haste
Whenever this creature attacks, creatures you control gain first strike and deathtouch until end of turn.

(: Add .)

Change the text of target permanent by replacing all instances of one color word with another or one basic land type with another. (For example, you may change "nonblack creature" to "nongreen creature" or "forestwalk" to "islandwalk." This effect lasts indefinitely.)

Psychic Blades — : Creatures you control get +2/+0 and gain menace until end of turn. (A creature with menace can't be blocked except by two or more creatures.)

When this creature dies, it deals 3 damage to any target.

First strike
: This creature gains protection from the color of your choice until end of turn.

Enchant creature
Enchanted creature gets +3/+3 and attacks each combat if able.
When enchanted creature dies, this Aura deals 3 damage to that creature's controller.

Whenever you cast a historic spell, investigate. This ability triggers only once each turn. (Artifacts, legendaries, and Sagas are historic. To investigate, create a Clue token. It's an artifact with ", Sacrifice this token: Draw a card.")
Doctor's companion (You can have two commanders if the other is the Doctor.)

Flash
Defender