Exploding Minions -
Enchantment
Whenever a creature you control deals combat damage to a player, you may sacrifice that creature. If you do, it deals damage equal to its power to that player.


White aura -
Enchanted creature has flying and first strike.

Blue aura -
Enchanted creature has hexproof and prowess.

Black aura -
Enchanted creature has lifelink and deathtouch.

Red aura -
Enchanted creature has haste and menace.

Green aura -
Enchanted creature has vigilance and trample.

Blood Hymn

Enchantment
Creatures you control have lifelink.

Thalnos's Discipline

Enchantment
If a spell you control would deal damage to a creature or player, that spell deals that much damage plus 1 instead.

Bountiful Garden

Enchantment
At the beginning of your upkeep, put a +1/+1 counter on target creature you control.

Bloodmage Thalnos, you say?!?!

Mammoth Growth —
Instant (U)
Put three +1/+1 counters on target creature.
The centaur of Marrowdyne draw their wisdom from the might of the mammoth around them. They believe the world is held in a cosmic mammoth's tusks.

Crazed Cerodon
Creature-Beast (U)
Haste, menace
When ~ enters the battlefield, target creature can't block this turn
2/2

Cadet Corps
Enchantment
At the beginning of your upkeep, create a 1/1 white Soldier creature token.

Cadet Corps Onna Stick
Creature - Human Soldier
At the beginning of your upkeep, create a 1/1 white Soldier creature token.
1/1

Mistress of Razors
Creature - Cat Warrior
When Mistress of Razors enters the battlefield, other creatures you control get +1/+0 until end of turn.
2/1

Plague
Sorcery
All creatures get -X/-X until end of turn.

We already have Black Sun's Zenith, but I'm surprised we don't have this more generic version.

Brink of Existence
Land (U)
: Add to your mana pool.
, , Sacrifice Brink of Existence: Destroy target permanent.
Where the physical world meets oblivion.

Mana Splicing -
Enchantment
Whenever a nontoken creature enters the battlefield under your control, add mana equal to that creature's mana cost to your mana pool. Spend this mana only to cast instant or sorcery spells.


I was thinking of creating a thread titled "cards that unsurprisingly don't exist" but decided this thread will do

Viridian Myr
Artifact Creature-Myr (C)
(Mark-Phyexian)
1/1

I feel like the main reason this doesn't exist is Memnite. You could probably upgrade your card to a 1/2 without making it overpowered, though.

Flight of the Valkyries
Enchantment (U)
Creatures you control have Flying.
Cycling

Imperial March
Enchantment (U)
Creatures you control have Deathtouch.
Cycling

Baba Yetu
Enchantment (U)
Creatures you control have Lifelink.
Cycling

Passion Tango
Enchantment (U)
Creatures you control have First Strike.
Cycling

The Lonely Shepherd
Enchantment (U)
Creatures you control have Vigilance.
Cycling

Multidenial

Instant
Counter X target spells.

Ooze's Revelation

Instant
Draw X cards. Create a X/X green Ooze creature token.

Overgrown Hydra

Creature -- Hydra
0/0
Overgrown Hydra enters the battlefield with twice X +1/+1 counters on it.

Burn Down

Instant
Burn Down deals X damage to target creature or planeswalker.

Look Within

Instant
Scry X, then draw a card.

Refresh

Sorcery
As an additional cost to cast Refresh, discard X cards.
Draw X+1 cards.

Hag's Choice

Sorcery
Choose one --
* Target player loses X life.
* Target creature gets -X/-X until end of turn.

if I were designing this I'd give it Indestructible but that's just me

Also it might be confusing for new players re: saccing an indestructible permanent. But I guess that's nothing reminder text can't fix

Pummel sounds a little more direct damage to me. I don't think the "word" "embiggen" is taken yet.

Peaceful Haven
Land (R)
: Add one mana of any color. Peaceful Haven doesn't untap during your next untap step.

Aggrandize would be a good name for that card.

Ten Steps Ahead —
Sorcery (U)
Scry 10.
"You act as if I hadn't thought of that already."
—Ertai, wizard adept