Lava Spike

Lava Spike deals 3 damage to target player or planeswalker.

Lightning Bolt

Lightning Bolt deals 3 damage to any target.

Plaguecrafter

When Plaguecrafter enters, each player sacrifices a creature or planeswalker of their choice. Each player who can't discards a card.

Entomb

Search your library for a card, put that card into your graveyard, then shuffle.

Doomsday

Search your library and graveyard for five cards and exile the rest. Put the chosen cards on top of your library in any order. You lose half your life, rounded up.

Thoughtseize

Target player reveals their hand. You choose a nonland card from it. That player discards that card. You lose 2 life.

Dark Ritual

Carrion Feeder

Carrion Feeder can't block.
Sacrifice a creature: Put a +1/+1 counter on Carrion Feeder.

Ragemonger

Minotaur spells you cast cost {B}{R} less to cast. This effect reduces only the amount of colored mana you pay. (For example, if you cast a Minotaur spell with mana cost {2}{R}, it costs {2} to cast.)

Magar of the Magic Strings

{1}{B}{R}: Note the name of target instant or sorcery card in your graveyard and put it onto the battlefield face down. It's a 3/3 creature with "Whenever this creature deals combat damage to a player, you may create a copy of the card with the noted name. You may cast the copy without paying its mana cost" and "If this creature would leave the battlefield, exile it instead of putting it anywhere else."

Obosh, the Preypiercer

Companion — Your starting deck contains only cards with odd mana values and land cards. (If this card is your chosen companion, you may put it into your hand from outside the game for {3} as a sorcery.)
If a source you control with an odd mana value would deal damage to a permanent or player, it deals double that damage to that permanent or player instead.