Bloodthirsty Adversary

Haste
When Bloodthirsty Adversary enters, you may pay {2}{R} any number of times. When you pay this cost one or more times, put that many +1/+1 counters on Bloodthirsty Adversary, then exile up to that many target instant and/or sorcery cards with mana value 3 or less from your graveyard and copy them. You may cast any number of the copies without paying their mana costs.

Den of the Bugbear

If you control two or more other lands, Den of the Bugbear enters tapped.
{T}: Add {R}.
{3}{R}: Until end of turn, Den of the Bugbear becomes a 3/2 red Goblin creature with "Whenever this creature attacks, create a 1/1 red Goblin creature token that's tapped and attacking." It's still a land.

Cemetery Gatekeeper

First strike
When Cemetery Gatekeeper enters, exile a card from a graveyard.
Whenever a player plays a land or casts a spell, if it shares a card type with the exiled card, Cemetery Gatekeeper deals 2 damage to that player.

Flameskull

Flying
Flameskull can't block.
Rejuvenation — When Flameskull dies, exile it. If you do, exile the top card of your library. Until the end of your next turn, you may play one of those cards. (If you cast Flameskull this way, you can't play the other card, and vice versa.)

Play with Fire

Play with Fire deals 2 damage to any target. If a player is dealt damage this way, scry 1. (Look at the top card of your library. You may put that card on the bottom.)

Mountain

Reinforced Ronin

Haste
At the beginning of your end step, return Reinforced Ronin to its owner's hand.
Channel — {1}{R}, Discard Reinforced Ronin: Draw a card.

Etching of Kumano

Haste
If a creature dealt damage this turn by a source you controlled would die, exile it instead.

Kumano Faces Kakkazan

(As this Saga enters and after your draw step, add a lore counter.)
I — Kumano Faces Kakkazan deals 1 damage to each opponent and each planeswalker they control.
II — When you next cast a creature spell this turn, that creature enters with an additional +1/+1 counter on it.
III — Exile this Saga, then return it to the battlefield transformed under your control.

Kumano Faces Kakkazan // Etching of Kumano

Chandra, Dressed to Kill

+1: Add {R}. Chandra, Dressed to Kill deals 1 damage to up to one target player or planeswalker.
+1: Exile the top card of your library. If it's red, you may cast it this turn.
−7: Exile the top five cards of your library. You may cast red spells from among them this turn. You get an emblem with "Whenever you cast a red spell, this emblem deals X damage to any target, where X is the amount of mana spent to cast that spell."

Sokenzan, Crucible of Defiance

{T}: Add {R}.
Channel — {3}{R}, Discard Sokenzan, Crucible of Defiance: Create two 1/1 colorless Spirit creature tokens. They gain haste until end of turn. This ability costs {1} less to activate for each legendary creature you control.

Kessig Wolfrider

Menace
{2}{R}, {T}, Exile three cards from your graveyard: Create a 3/2 red Wolf creature token.

Ancestral Anger

Target creature gains trample and gets +X/+0 until end of turn, where X is 1 plus the number of cards named Ancestral Anger in your graveyard. (A creature with trample can deal excess combat damage to the player or planeswalker it's attacking.)
Draw a card.

Reckless Impulse

Exile the top two cards of your library. Until the end of your next turn, you may play those cards.