Choose one or both —
• Brink of the End deals X damage to target creature or planeswalker.
• Target player loses X life.

Whenever another creature you control enters, Broken Steelbeak gains flying until end of turn.

Whenever Brot, Head Honcho or another Minion you control dies, you draw a card and lose 1 life.

This spell costs {1} less to cast if you've cast another spell that targeted a creature this turn.
Target creature you control gets +4/+4 until end of turn.

This spell costs {4} more to cast if it's your turn.
Return target nonland permanent to its owner's hand. If it's your turn, return up to two target nonland permanents to their owners' hands instead.

Target creature gets +3/+1 and gains trample until end of turn.

Experience
When Budding Companion has three or more +1/+1 counters on it, remove them all and transform it.

Destroy target creature with flying.

Counter target spell unless its controller pays {2}. Until end of turn, spells your opponents cast cost {1} more to cast.

Whenever a player finishes exiling cards from anywhere, each opponent loses 1 life.
{2}{B}: Level 2
At the beginning of your upkeep, exile the top card of target opponent's library face down. You may look at it for as long as it remains exiled.
{3}{B}: Level 3
You may cast spells exiled with this Class. Those spells cost {1} less to cast, and mana of any type can be spent to cast those spells.

Lifelink, haste
Whenever Calamity's Cohort attacks, exile the top card of defending player's library. You may cast that card for as long as it remains exiled, and mana of any type can be spent to cast that spell. Spend only mana from artifacts to cast that spell.

As an additional cost to cast this spell, sacrifice a creature.
Caldera's Gift deals 3 damage to target creature or planeswalker and you gain 3 life.

You may cast target instant or sorcery card from your graveyard this turn. If that spell would be put into your graveyard, exile it instead.

Whenever an opponent sacrifices a permanent, put a +1/+1 counter on Callous Tactician and that player loses 1 life.
{3}{B}: Each player sacrifices a creature.

Whenever a creature you control dies during your turn, you may exile the top card of your library. You may play that card until you exile another card with Campaign of Retribution.

You may cast creature spells as though they had flash.
At the beginning of your end step, you may shuffle a creature you control into its owner's library. If you do, draw a card, then untap up to two lands.

Whenever you attack, you may cast an Aura card from your graveyard if that spell targets an attacking creature.

Target creature you control gets +2/+0 and gains lifelink until end of turn. When that creature dies this turn, draw a card.

Flying
When Caravan Skyrider enters, you may return another permanent you control to its owner's hand.

When Cardboard Box enters, draw a card.
Spells that target you cost {2} more to cast.
{T}, Sacrifice Cardboard Box: Untap target creature that's attacking you and remove it from combat.

Deathtouch
When Carrion Viper enters, you may discard a card. When you do, return target creature card from your graveyard to your hand.

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

When Catscratch Broker enters, each opponent sacrifices an enchantment.

When Cawyer Station Veteran dies, you may put a +1/+1 counter on target creature you control.

As an additional cost to cast this spell, exile X creature cards from your graveyard.
Each opponent sacrifices a creature with toughness X or greater.