Desperate Ritual

Add {R}{R}{R}.
Splice onto Arcane {1}{R} (As you cast an Arcane spell, you may reveal this card from your hand and pay its splice cost. If you do, add this card's effects to that spell.)

Mountain

Hellkite Overlord

Flying, trample, haste
{R}: Hellkite Overlord gets +1/+0 until end of turn.
{B}{G}: Regenerate Hellkite Overlord.

Cathartic Reunion

As an additional cost to cast this spell, discard two cards.
Draw three cards.

Rite of Flame

Add {R}{R}, then add {R} for each card named Rite of Flame in each graveyard.

Faithless Looting

Draw two cards, then discard two cards.
Flashback {2}{R} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Irencrag Feat

Add seven {R}. You can cast only one more spell this turn.

Thrill of Possibility

As an additional cost to cast this spell, discard a card.
Draw two cards.

Seething Song

Miirym, Sentinel Wyrm

Flying, ward {2}
Whenever another nontoken Dragon you control enters, create a token that's a copy of it, except the token isn't legendary.

Dragonstorm

Search your library for a Dragon permanent card, put it onto the battlefield, then shuffle.
Storm (When you cast this spell, copy it for each spell cast before it this turn.)