Foreboding Ruins

As this land enters, you may reveal a Swamp or Mountain card from your hand. If you don't, this land enters tapped.
{T}: Add {B} or {R}.

Harmless Offering

Target opponent gains control of target permanent you control.

Mountain

Midnight Oil

This enchantment enters with seven hour counters on it.
At the beginning of your draw step, draw an additional card and remove two hour counters from this enchantment.
Your maximum hand size is equal to the number of hour counters on this enchantment.
Whenever you discard a card, you lose 1 life.

Archfiend of the Dross

Flying
This creature enters with four oil counters on it.
At the beginning of your upkeep, remove an oil counter from this creature. Then if it has no oil counters on it, you lose the game.
Whenever a creature an opponent controls dies, its controller loses 2 life.

Zombify

Return target creature card from your graveyard to the battlefield.

Bloodfell Caves

This land enters tapped.
When this land enters, you gain 1 life.
{T}: Add {B} or {R}.

Vile Entomber

Deathtouch (Any amount of damage this deals to a creature is enough to destroy it.)
When this creature enters, search your library for a card, put that card into your graveyard, then shuffle.

Swamp

Aether Snap

Remove all counters from all permanents and exile all tokens.

Alexios, Deimos of Kosmos

Trample
Alexios attacks each combat if able, can't be sacrificed, and can't attack its owner.
At the beginning of each player's upkeep, that player gains control of Alexios, untaps it, and puts a +1/+1 counter on it. It gains haste until end of turn.

Aggressive Mining

You can't play lands.
Sacrifice a land: Draw two cards. Activate only once each turn.

Rain of Tears

Bazaar Trader

{T}: Target player gains control of target artifact, creature, or land you control.