Mountain

Twinferno

Choose one —
• When you cast your next instant or sorcery spell this turn, copy that spell. You may choose new targets for the copy.
• Target creature you control gains double strike until end of turn. (It deals both first-strike and regular combat damage.)

Ragefire Hellkite

Flying
Whenever this creature attacks, you may sacrifice another creature. If you do, this creature gains double strike until end of turn.

Flowstone Kavu

Menace (This creature can't be blocked except by two or more creatures.)
{R}: This creature gets +1/-1 until end of turn.

Jaya's Firenado

Jaya's Firenado deals 5 damage to target creature or planeswalker. Scry 1. (Look at the top card of your library. You may put that card on the bottom.)

Hammerhand

Enchant creature
When this Aura enters, target creature can't block this turn.
Enchanted creature gets +1/+1 and has haste.

Lightning Strike

Lightning Strike deals 3 damage to any target.

Ready to Attack

Coalition Warbrute

Enlist (As this creature attacks, you may tap a nonattacking creature you control without summoning sickness. When you do, add its power to this creature's until end of turn.)
Trample

Phoenix Chick

Flying, haste
This creature can't block.
Whenever you attack with three or more creatures, you may pay {R}{R}. If you do, return this card from your graveyard to the battlefield tapped and attacking with a +1/+1 counter on it.

Goblin Picker

Dragon Whelp

Flying
{R}: This creature gets +1/+0 until end of turn. If this ability has been activated four or more times this turn, sacrifice this creature at the beginning of the next end step.

Electrostatic Infantry

Trample
Whenever you cast an instant or sorcery spell, put a +1/+1 counter on this creature.

The Elder Dragon War

Read ahead (Choose a chapter and start with that many lore counters. Add one after your draw step. Skipped chapters don't trigger. Sacrifice after III.)
I — This Saga deals 2 damage to each creature and each opponent.
II — Discard any number of cards, then draw that many cards.
III — Create a 4/4 red Dragon creature token with flying.