Ziatora's Envoy

Trample
Whenever Ziatora's Envoy deals combat damage to a player, look at the top card of your library. You may play a land from the top of your library or cast a spell with mana value less than or equal to the damage dealt from the top of your library without paying its mana cost. If you don't, put that card into your hand.
Blitz {2}{B}{R}{G}

Immolation Shaman

Whenever an opponent activates an ability of an artifact, creature, or land that isn't a mana ability, Immolation Shaman deals 1 damage to that player.
{3}{R}{R}: Immolation Shaman gets +3/+3 and gains menace until end of turn.

Mezzio Mugger

Whenever Mezzio Mugger attacks, exile the top card of each player's library. You may play those cards this turn, and you may spend mana as though it were mana of any color to cast those spells.
Blitz {2}{R} (If you cast this spell for its blitz cost, it gains haste and "When this creature dies, draw a card." Sacrifice it at the beginning of the next end step.)

Riveteers Requisitioner

When Riveteers Requisitioner dies, create a Treasure token. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")
Blitz {2}{R} (If you cast this spell for its blitz cost, it gains haste and "When this creature dies, draw a card." Sacrifice it at the beginning of the next end step.)

Viashino Heretic

{1}{R}, {T}: Destroy target artifact. Viashino Heretic deals damage to that artifact's controller equal to the artifact's mana value.

Mindclaw Shaman

When Mindclaw Shaman enters, target opponent reveals their hand. You may cast an instant or sorcery spell from among those cards without paying its mana cost.

Yurlok of Scorch Thrash

Vigilance
A player losing unspent mana causes that player to lose that much life.
{1}, {T}: Each player adds {B}{R}{G}.

Carrion Thrash

When Carrion Thrash dies, you may pay {2}. If you do, return another target creature card from your graveyard to your hand.

Riveteers Initiate

{1}{B/G}: Riveteers Initiate gains deathtouch until end of turn.

Thrashing Frontliner

Trample
Whenever Thrashing Frontliner attacks a battle, it gets +1/+1 until end of turn.

Viashino Shanktail

First strike
Bloodrush — {2}{R}, Discard Viashino Shanktail: Target attacking creature gets +3/+1 and gains first strike until end of turn.

Dagger Caster

When Dagger Caster enters, it deals 1 damage to each opponent and 1 damage to each creature your opponents control.

Ognis, the Dragon's Lash

Haste
Whenever a creature you control with haste attacks, create a tapped Treasure token.

Viashino Lashclaw

{T}, Discard a card: Creatures you control gain haste until end of turn.

Viashino Pyromancer

When this creature enters, it deals 2 damage to target player or planeswalker.

Viashino Branchrider

Kicker {2}{G} (You may pay an additional {2}{G} as you cast this spell.)
Haste
If Viashino Branchrider was kicked, it enters with two +1/+1 counters on it.
{2}{R}: Viashino Branchrider gets +2/+0 until end of turn.

Viashino Sandsprinter

Trample, haste
At the beginning of the end step, return Viashino Sandsprinter to its owner's hand. (Return it only if it's on the battlefield.)
Cycling {R} ({R}, Discard this card: Draw a card.)