Menace
Whenever one or more creatures you control deal combat damage to a player, create a Food token.
Whenever you sacrifice a Food, put a +1/+1 counter on this creature.
When this creature leaves the battlefield, target opponent loses life equal to its power.

When you cast this spell, you gain half X life and draw half X cards. Round down each time.
Flying, trample
This creature enters with X +1/+1 counters on it.

Whenever a Zombie or Mutant you control dies, if its power was different from its base power, draw a card.
Come Fly With Me — , Sacrifice a creature: Put a +1/+1 counter on target creature you control. It gains flying until end of turn.

Equipped creature can't be blocked and has shroud. (It can't be the target of spells or abilities.)
Equip

, , Sacrifice Mindslaver: You control target player during that player's next turn. (You see all cards that player could see and make all decisions for them.)

Protection from permanents with corruption counters on them
+1: Each opponent loses 2 life and you gain 2 life. Put a corruption counter on up to one other target creature or planeswalker.
−3: Gain control of target creature or planeswalker until end of turn. Untap it and put a corruption counter on it. It gains haste until end of turn.
−7: Gain control of each permanent with a corruption counter on it.

Destroy target artifact you don't control.
Overload (You may cast this spell for its overload cost. If you do, change "target" in its text to "each.")

Living weapon (When this Equipment enters, create a 0/0 black Phyrexian Germ creature token, then attach this to it.)
Equipped creature gets +4/+4 and has vigilance and lifelink.
: Return this Equipment to its owner's hand.
Equip

Magecraft — Whenever you cast or copy an instant or sorcery spell, draw a card.

When this creature enters or leaves the battlefield, choose a land of each basic land type, then destroy those lands.

Create two 1/1 blue Merfolk Wizard creature tokens.
Tap four untapped Merfolk you control: Return this card from your graveyard to your hand.

Whenever you cast an instant or sorcery spell, create a 2/2 black Zombie creature token with decayed. (It can't block. When it attacks, sacrifice it at end of combat.)
At the beginning of your upkeep, if you control three or more creature tokens, you may transform this creature.

, Remove a counter from a permanent you control: Choose one —
• Put a charge counter on target artifact.
• Put a +1/+1 counter on target creature.

Enchant player
Whenever enchanted player is attacked, create a 2/2 black Zombie creature token. Each opponent attacking that player does the same.

Flash (You may cast this spell any time you could cast an instant.)
Flying
Spells you cast with mana value 5 or greater cost less to cast and can't be countered.

Other creatures you control have haste.
Artifact cards and red creature cards in your hand have warp . (You may cast a card from your hand for its warp cost. Exile that permanent at the beginning of the next end step, then you may cast it from exile on a later turn.)

Infect (This creature deals damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)
When this creature enters, each player gets a poison counter.

: Add one mana of any color in your commander's color identity.

(Gain the next level as a sorcery to add its ability.)
Whenever one or more creatures you control die, create a Food token. This ability triggers only once each turn.
: Level 2
Whenever you sacrifice a permanent, target player mills two cards.
: Level 3
At the beginning of your end step, you may sacrifice three other nonland permanents. If you do, return a creature card from your graveyard to the battlefield with a finality counter on it.

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after IV.)
I — Destroy up to one target nonland permanent.
II, III — Each opponent loses 2 life.
IV — Create Galactus, a legendary 16/16 black Elder Alien creature token with flying, trample, and "Whenever Galactus attacks, destroy target land."