Search your library for up to three creature cards, put them into your graveyard, then shuffle your library.

Flying
Whenever Butcher of Malakir or another creature you control dies, each opponent sacrifices a creature.

Create a 5/5 blue and red Elemental creature token with flying.
Retrace (You may cast this card from your graveyard by discarding a land card in addition to paying its other costs.)

At the beginning of each upkeep, you gain 3 life.

Chain Reaction deals X damage to each creature, where X is the number of creatures on the battlefield.

Equipped creature gets +2/+2.
As long as equipped creature is legendary, it has hexproof. (It can't be the target of spells or abilities your opponents control.)
Equip

The owner of target permanent shuffles it into their library, then reveals the top card of their library. If it's a permanent card, they put it onto the battlefield.

: Chartooth Cougar gets +1/+0 until end of turn.
Mountaincycling (, Discard this card: Search your library for a Mountain card, reveal it, put it into your hand, then shuffle your library.)

Forestwalk (This creature can't be blocked as long as defending player controls a Forest.)
As an additional cost to cast creature spells, you may pay any amount of mana. If you do, that creature enters the battlefield with that many additional +1/+1 counters on it.

Morph (You may cast this card face down as a 2/2 creature for . Turn it face up any time for its morph cost.)
When Chromeshell Crab is turned face up, you may exchange control of target creature you control and target creature an opponent controls.

Radiance — Cleansing Beam deals 2 damage to target creature and each other creature that shares a color with it.

If a noncreature permanent under your control was destroyed this turn by a spell or ability an opponent controlled, you may pay rather than pay this spell's mana cost.
Create four 1/1 green Snake creature tokens.

Join forces — Starting with you, each player may pay any amount of mana. Each player searches their library for up to X basic land cards, where X is the total amount of mana paid this way, puts them onto the battlefield tapped, then shuffles their library.

Target creature gets +4/+2 and gains trample until end of turn.

Multikicker (You may pay an additional any number of times as you cast this spell.)
Choose any target, then choose another target for each time this spell was kicked. Comet Storm deals X damage to each of them.

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

Target player gains 2 life for each creature on the battlefield.

Flying
Whenever Conundrum Sphinx attacks, each player chooses a card name. Then each player reveals the top card of their library. If the card a player revealed has the name they chose, that player puts it into their hand. If it doesn't, that player puts it on the bottom of their library.

Vigilance
When Court Hussar enters the battlefield, look at the top three cards of your library, then put one of them into your hand and the rest on the bottom of your library in any order.
When Court Hussar enters the battlefield, sacrifice it unless was spent to cast it.

At the beginning of each upkeep, put a strife counter on Crescendo of War.
Attacking creatures get +1/+0 for each strife counter on Crescendo of War.
Blocking creatures you control get +1/+0 for each strife counter on Crescendo of War.