Bogardan Hellkite

Flash
Flying
When Bogardan Hellkite enters, it deals 5 damage divided as you choose among any number of targets.

Combustible Gearhulk

First strike
When Combustible Gearhulk enters, target opponent may have you draw three cards. If the player doesn't, you mill three cards, then Combustible Gearhulk deals damage to that player equal to the total mana value of those cards.

Jaxis, the Troublemaker

{R}, {T}, Discard a card: Create a token that's a copy of another target creature you control. It gains haste and "When this creature dies, draw a card." Sacrifice it at the beginning of the next end step. Activate only as a sorcery.
Blitz {1}{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.)

Brallin, Skyshark Rider

Partner with Shabraz, the Skyshark (When this creature enters, target player may put Shabraz into their hand from their library, then shuffle.)
Whenever you discard a card, put a +1/+1 counter on Brallin, Skyshark Rider and it deals 1 damage to each opponent.
{R}: Target Shark gains trample until end of turn.

Bedlam Reveler

This spell costs {1} less to cast for each instant and sorcery card in your graveyard.
Prowess
When Bedlam Reveler enters, discard your hand, then draw three cards.

Ardent Elementalist

When Ardent Elementalist enters, return target instant or sorcery card from your graveyard to your hand.

Circuit Mender

When Circuit Mender enters, you gain 2 life.
When Circuit Mender leaves the battlefield, draw a card.

Burning Sun's Avatar

When Burning Sun's Avatar enters, it deals 3 damage to target opponent or planeswalker and 3 damage to up to one target creature.

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.

Cavalier of Flame

{1}{R}: Creatures you control get +1/+0 and gain haste until end of turn.
When Cavalier of Flame enters, discard any number of cards, then draw that many cards.
When Cavalier of Flame dies, it deals X damage to each opponent and each planeswalker they control, where X is the number of land cards in your graveyard.