Manifest dread X times, then put X +1/+1 counters on each of those creatures. (To manifest dread, look at the top two cards of your library, then put one onto the battlefield face down as a 2/2 creature and the other into your graveyard. Turn it face up any time for its mana cost if it's a creature card.)

Hexproof (This creature can't be the target of spells or abilities your opponents control.)
Whenever a creature dies, put a +1/+1 counter on this creature.

Whenever you cast an instant or sorcery spell that targets only Bill Potts or activate an ability that targets only Bill Potts, copy that spell or ability. You may choose new targets for the copy. This ability triggers only once each turn.
Doctor's companion (You can have two commanders if the other is the Doctor.)

This land enters tapped.
: Add , , or .

Exile target creature. Its controller manifests the top card of their library. (That player puts the top card of their library onto the battlefield face down as a 2/2 creature. If it's a creature card, it can be turned face up any time for its mana cost.)

: Exile target creature. Return that card to the battlefield under its owner's control at the beginning of the next end step.

Choose one or both —
• The owner of target nonland permanent puts it on their choice of the top or bottom of their library.
• Return target nonland permanent to its owner's hand.

Whenever a player casts a green spell, you may gain 1 life.

Delve (Each card you exile from your graveyard while casting this spell pays for .)
Flying
, , Exile X cards from your graveyard: Target creature gets -X/-X until end of turn.

: Monstrosity 2. (If this creature isn't monstrous, put two +1/+1 counters on it and it becomes monstrous. can be paid with one mana from a snow source.)
As long as this creature is monstrous, it has flying.

: This creature deals 1 damage to target player or planeswalker.

Improvise (Your artifacts can help cast this spell. Each artifact you tap after you're done activating mana abilities pays for .)
Flying

At the beginning of combat on your turn, put a +1/+1 counter on target creature you control.
Whenever another nontoken Soldier you control dies, create a 1/1 colorless Soldier artifact creature token.

Draw X cards. Then you may put a permanent card with mana value X or less from your hand onto the battlefield tapped.

, , Sacrifice this creature: It deals X damage to any target.

Whenever Baxter enters or attacks, each creature you control with a counter on it gains flying until end of turn.
Whenever you draw a card, put a +1/+1 counter on Baxter.

Sacrifice an artifact or creature: Put a +1/+1 counter on this creature. Activate only as a sorcery.

Tap an untapped Wizard you control: Draw a card.

Flying
When this creature enters, exile another target permanent. Return that card to the battlefield under its owner's control at the beginning of the next end step.

Destroy target creature. Its controller discards a card.