Neheb, Dreadhorde Champion

Trample
Whenever Neheb, Dreadhorde Champion deals combat damage to a player or planeswalker, you may discard any number of cards. If you do, draw that many cards and add that much {R}. Until end of turn, you don't lose this mana as steps and phases end.

Have

Markov Waltzer

Flying, haste
At the beginning of combat on your turn, up to two target creatures you control each get +1/+0 until end of turn.

Angel of Serenity

Flying
When Angel of Serenity enters, you may exile up to three other target creatures from the battlefield and/or creature cards from graveyards.
When Angel of Serenity leaves the battlefield, return the exiled cards to their owners' hands.

City on Fire

Convoke (Your creatures can help cast this spell. Each creature you tap while casting this spell pays for {1} or one mana of that creature's color.)
If a source you control would deal damage to a permanent or player, it deals triple that damage instead.

Thrill of Possibility

As an additional cost to cast this spell, discard a card.
Draw two cards.

Stranglehold

Your opponents can't search libraries.
If an opponent would begin an extra turn, that player skips that turn instead.

Avacyn, the Purifier

Flying
When this creature transforms into Avacyn, the Purifier, it deals 3 damage to each other creature and each opponent.

Archangel Avacyn

Flash
Flying, vigilance
When Archangel Avacyn enters, creatures you control gain indestructible until end of turn.
When a non-Angel creature you control dies, transform Archangel Avacyn at the beginning of the next upkeep.

Archangel Avacyn // Avacyn, the Purifier

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.)

Breath of Fury

Enchant creature you control
When enchanted creature deals combat damage to a player, sacrifice it and attach Breath of Fury to a creature you control. If you do, untap all creatures you control and after this phase, there is an additional combat phase.

Iroas, God of Victory

Indestructible
As long as your devotion to red and white is less than seven, Iroas isn't a creature.
Creatures you control have menace.
Prevent all damage that would be dealt to attacking creatures you control.

Winota, Joiner of Forces

Whenever a non-Human creature you control attacks, look at the top six cards of your library. You may put a Human creature card from among them onto the battlefield tapped and attacking. It gains indestructible until end of turn. Put the rest of the cards on the bottom of your library in a random order.

Spikewheel Acrobat

Spectacle {2}{R} (You may cast this spell for its spectacle cost rather than its mana cost if an opponent lost life this turn.)

Angelic Quartermaster

Flying
When Angelic Quartermaster enters, put a +1/+1 counter on each of up to two other target creatures.

Taurean Mauler

Changeling (This card is every creature type.)
Whenever an opponent casts a spell, you may put a +1/+1 counter on this creature.