Drannith Magistrate

Your opponents can't cast spells from anywhere other than their hands.

Boil

Dwarven Pony

{1}{R}, {T}: Target Dwarf creature gains mountainwalk until end of turn. (It can't be blocked as long as defending player controls a Mountain.)

Diamond Mare

As Diamond Mare enters the battlefield, choose a color.
Whenever you cast a spell of the chosen color, you gain 1 life.

Omen Machine

Players can't draw cards.
At the beginning of each player's draw step, that player exiles the top card of their library. If it's a land card, the player puts it onto the battlefield. Otherwise, the player casts it without paying its mana cost if able.

Jandor's Saddlebags

Shadowfax, Lord of Horses

Horses you control have haste. (They can attack and {T} as soon as they come under your control.)
Whenever Shadowfax, Lord of Horses attacks, you may put a creature card with lesser power from your hand onto the battlefield tapped and attacking.

Karlach, Fury of Avernus

Whenever you attack, if it's the first combat phase of the turn, untap all attacking creatures. They gain first strike until end of turn. After this phase, there is an additional combat phase.
Choose a Background (You can have a Background as a second commander.)

Luminarch Aspirant

At the beginning of combat on your turn, put a +1/+1 counter on target creature you control.

Militia Bugler

Vigilance (Attacking doesn't cause this creature to tap.)
When Militia Bugler enters the battlefield, look at the top four cards of your library. You may reveal a creature card with power 2 or less from among them and put it into your hand. Put the rest on the bottom of your library in a random order.

Fire-Belly Changeling

Changeling (This card is every creature type.)
{R}: Fire-Belly Changeling gets +1/+0 until end of turn. Activate no more than twice each turn.

Adaptive Automaton

As Adaptive Automaton enters the battlefield, choose a creature type.
Adaptive Automaton is the chosen type in addition to its other types.
Other creatures you control of the chosen type get +1/+1.

Crested Sunmare

Other Horses you control have indestructible.
At the beginning of each end step, if you gained life this turn, create a 5/5 white Horse creature token.