Flames of WarR
Instant [U]
Flames of War deals 2 damage to any target. Warlike — Flames of War deals 3 damage to that permanent or player instead if a creature you control dealt combat damage this turn. Nothing stokes the Boros’ flames like a battle.
So a card with "+1: ~ becomes a colorless Forest land until end of turn" doesn't meet the main challenge because it comes from a loyalty ability? Sorry if I'm bothering you, I'm just making sure.
Laurel, Wandering GroveGGG
Legendary Planeswalker - Laurel [M]
At the beginning of your upkeep, you may have Laurel, Wandering Grove become a colorless Forest land until your next turn.
+1: Put three +1/+1 counters on up to one target Forest you control and it becomes a 0/0 Dryad creature with hexproof. It’s still a land.
-8: Gain control of all nonbasic lands. They become Forests in addition to their other types.
3
Harmonious Garden
Land [R] T: Add one mana of any color. Target opponent gains 2 life. Though few reap it's fruit, all benefit from its presence.
An activated ability is a mana ability if it meets all of the following criteria: it doesn’t have a target, it could add mana to a player’s mana pool when it resolves, and it’s not a loyalty ability.
So when you said it didn't have to be a creature, you meant it still had to be able to turn into a creature with persist. I want to complain, but since no one else made that mistake, I think the only problem is with my reading comprehension skills.
Unending Endeavor4W
Enchantment [U]
Each creature you control has persist. (When it dies, if it had no -1/-1 counters on it, return it to the battlefield under its owner's control with a -1/-1 counter on it.) "There will be no rest as long as our Great Work remains incomplete."
—Elesh Norn, Mother of Machines
Aurelia's Last Stand1RW
Legendary Sorcery [M] (You may cast a legendary sorcery only if you control a legendary creature or planeswalker.)
Kicker—Pay life equal to your life total minus 1.
Create three 1/1 red and white Soldier creature tokens with haste. Aurelia's Last Stand deals 3 damage to target creature. If this spell was kicked, instants, other sorceries, and creatures you control gain lifelink until end of turn.
The Champion's Trials 3WW
Enchantment — Saga [M] (As this Saga enters and after your draw step, add a lore counter. Sacrifice after IV.)
I — Destroy target creature with power 4 or greater.
II — Create three 1/1 white Soldier creature tokens.
III — Exile up to one target creature or enchantment. You get an emblem with “Players can’t cast spells with the same name as cards in exile.”
IV — Each player sacrifices a planeswalker.
Flames of War R
Instant [U]
Flames of War deals 2 damage to any target.
Warlike — Flames of War deals 3 damage to that permanent or player instead if a creature you control dealt combat damage this turn.
Nothing stokes the Boros’ flames like a battle.
Legendary Planeswalker - Laurel [M]
At the beginning of your upkeep, you may have Laurel, Wandering Grove become a colorless Forest land until your next turn.
+1: Put three +1/+1 counters on up to one target Forest you control and it becomes a 0/0 Dryad creature with hexproof. It’s still a land.
-8: Gain control of all nonbasic lands. They become Forests in addition to their other types.
3
Land [R]
T: Add one mana of any color. Target opponent gains 2 life.
Though few reap it's fruit, all benefit from its presence.
Enchantment [U]
Each creature you control has persist. (When it dies, if it had no -1/-1 counters on it, return it to the battlefield under its owner's control with a -1/-1 counter on it.)
"There will be no rest as long as our Great Work remains incomplete."
—Elesh Norn, Mother of Machines
Legendary Sorcery [M]
(You may cast a legendary sorcery only if you control a legendary creature or planeswalker.)
Kicker—Pay life equal to your life total minus 1.
Create three 1/1 red and white Soldier creature tokens with haste. Aurelia's Last Stand deals 3 damage to target creature. If this spell was kicked, instants, other sorceries, and creatures you control gain lifelink until end of turn.
Enchantment — Saga [M]
(As this Saga enters and after your draw step, add a lore counter. Sacrifice after IV.)
I — Destroy target creature with power 4 or greater.
II — Create three 1/1 white Soldier creature tokens.
III — Exile up to one target creature or enchantment. You get an emblem with “Players can’t cast spells with the same name as cards in exile.”
IV — Each player sacrifices a planeswalker.
Electrickery is a fun card and pretty good for what it is, but it's no Cyclonic Rift or even Mizzium Mortars.