Storm-Kiln Artist

This creature gets +1/+0 for each artifact you control.
Magecraft — Whenever you cast or copy an instant or sorcery spell, create a Treasure token.

Chatterstorm

Create a 1/1 green Squirrel creature token.
Storm (When you cast this spell, copy it for each spell cast before it this turn.)

Battle Hymn

Rite of Flame

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

Galvanic Relay

Exile the top card of your library. During your next turn, you may play that card.
Storm (When you cast this spell, copy it for each spell cast before it this turn.)

Mana Geyser

Add {R} for each tapped land your opponents control.

Seething Song

Pyretic Ritual

Mana Flare

Whenever a player taps a land for mana, that player adds one mana of any type that land produced.

Empty the Warrens

Create two 1/1 red Goblin creature tokens.
Storm (When you cast this spell, copy it for each spell cast before it this turn.)

Mana Seism

Sacrifice any number of lands, then add that much {C}.

Runaway Steam-Kin

Whenever you cast a red spell, if this creature has fewer than three +1/+1 counters on it, put a +1/+1 counter on this creature.
Remove three +1/+1 counters from this creature: Add {R}{R}{R}.

Radha, Heir to Keld

Whenever Radha attacks, you may add {R}{R}.
{T}: Add {G}.

Simian Spirit Guide

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.)

Koth of the Hammer

+1: Untap target Mountain. It becomes a 4/4 red Elemental creature until end of turn. It's still a land.
−2: Add {R} for each Mountain you control.
−5: You get an emblem with "Mountains you control have '{T}: This land deals 1 damage to any target.'"