Taking a little break from Norse stuff.

Seize the Throne

Sorcery (M)
Target opponent chooses a creature they control, then untap each other creature they control and gain control of them until end of turn. They gain haste until end of turn.
"We've come to talk, your majesty."

If I'm reading this correctly, this is missing a "you" somewhere.

Something like this: "Target opponent chooses a creature they control. You gain control of each other creature that player controls until end of turn. Untap tap those creatures. They gain haste until end of turn."

I pretty much just copy and pasted the text from Insurrection and added a few words. I'm a good cardmaker.

The difference between this design and Insurrection is that this design requires both you and the opponent to take actions. This leaves the Insurrection portion of the ability to be unclear who is untapping and gaining control. I'd just add a "you" in there somewhere to remove this ambiguity.

Yeah, I could see some confusion arising. I agree that the clarity is worth the addition of a single word. Consider it added (though I'm not gonna edit the original post).

One of my more ambitious worldbuilding endeavors revolves around a twin pair of planes. One (so far unnamed) is largely under the control of a secretive but all-powerful organization known as the Dominion. Mages there have discovered a way to open interplanar portals, but the trip appears to be one-way only. This technique is widely used to rid of any undesirables -- be it garbage, dangerous fauna, or enemies of the Dominion. The mood of this plane would be inspired by Orwell and other dystopian fiction.

Where does all of this offal end up? On Termidel, a desolate wasteland that was uninhabited by any sentient beings until exiles started being dropped off there generations ago. The people here scrape out a living with whatever they can find. Randomly-opening portals in the sky often drop new residents or valuable scrap that various factions fight to possess. This would be Magic meets Mad Max.

The original design worked best with the old three-set blocks, where I could have the first two sets centered on one of the two planes and the third acting as a "collision of worlds" event.

Anyway, here are some cards showcasing the main mechanic of the Dominion:

Lockdown Enforcer

Creature -- Human Wizard (U)
When Lockdown Enforcer enters the battlefield, create a Law token, then exile target creature an opponent controls for as long as you control a Law. (It's an enchantment with “: Exile this. Any player may activate this ability during their turn.”)
2/3

Gossamer Agent

Creature -- Vedalken Rogue (C)
When Gossamer Agent enters the battlefield, create a Law token. (It's an enchantment with “: Exile this. Any player may activate this ability during their turn.”)
Gossamer Agent can't be blocked as long as you control a Law.
Noticing a Dominion spy is a punishable offense.
2/3

In the category of "surprised they haven't printed this before":

Heart of the Woods

Creature -- Dryad (R)
Creatures and lands you control have ": Add one mana of any color."
Druids draw their power from nature itself. Dryads have it easier: they are nature itself.
2/2

Now that the real Kaldheim has been fully spoiled, I'm going to wrap up my version of the set by posting some random odds-and-ends that I liked.

Devoted Innkeeper

Creature -- Human Advisor (U)
At the beginning of combat on your turn, you may tap another untapped creature you control. If you do, put a +1/+1 counter on it and it gains hexproof until the beginning of your next combat.
"Care for a rest, traveler?"
1/4

Fortress Builder

Creature -- Dwarf Articifer (R)
As long as you control four or more Walls, you and permanents you control have hexproof.
, , Discard a card: Create a 0/4 colorless Wall artifact creature token with defender named Steel Wall.
1/3

I'm 99% sure I've posted this one somewhere before (I think it even won CoTW)? I'm just posting it here for posterity because it's one of my favorite cards I've ever designed.

Mirror Stalker

Creature -- Shapeshifter (U)
You may have Mirror Stalker enter the battlefield as a copy of any creature on the battlefield, except its power and toughness are switched.
In a reflection there is perfect truth and perfect cruelty.
0/0



0/0
.γtlɘυɿɔ tɔɘʇɿɘq bnɒ ʜtυɿt tɔɘʇɿɘq ƨi ɘɿɘʜt noitɔɘlʇɘɿ ɒ nI
.bɘʜɔtiwƨ ɘɿɒ ƨƨɘnʜϱυot bnɒ ɿɘwoq ƨti tqɘɔxɘ ,blɘiʇɘlttɒd ɘʜt no ɘɿυtɒɘɿɔ γnɒ ʇo γqoɔ ɒ ƨɒ blɘiʇɘlttɒd ɘʜt ɿɘtnɘ ɿɘʞlɒtƧ ɿoɿɿiM ɘvɒʜ γɒm υoY
(U) ɿɘtʇiʜƨɘqɒʜƧ -- ɘɿυtɒɘɿƆ

ɿɘʞlɒtƧ ɿoɿɿiM

Just in case you might have a positive opinion of my cardmaking ability, I wanted to post something dumb.

Mother of Hexes

Creature -- Human Warlock (R)
: Choose target creature. Each other creature gains protection from that creature until end of turn.
"Your own family won't even want you now."
1/1

I don't even necessarily think that black is the best color for this ability, but it doesn't work as well as a Mother of Runes mirror in any other color.

More Commanders!

Athica, also known as the Peerless City, has enjoyed a long and storied existence. History books document the succession of rulers who shaped the city to what it is today -- from Mercalis the Uniter, who opened the gates to besieging army and brought a bloodless end to a war, to Elora the Shrewd, who negotiated with neighboring provinces and brought great wealth to her domain.

The texts tend to gloss over the era where a covetous dragon seized Athica's throne by force and acted as its de facto king for nearly a decade. Contrary to what may be expected, these years were marked by relative prosperity and peace. The dragon's rule ended when it decided to fly off of its own volition, never to be seen near the city again.

Rakosh the Conqueror

Legendary Creature -- Dragon (M)
Flying
Whene Rakosh the Conqueror enters the battlefield, untap target artifact or land and gain control of it.
Whenever you gain control of a permanent, Rakosh deals 3 damage to that permanent's owner.
6/6

Residents of the pale city of Demorra often say a small prayer before lifting any drink to their lips: "May I ever escape the snake's kiss." The superstition is generations old, far older than the apparent age of Eru Farr, the Snake of Demorra. But it is to her who the prayer is aimed.

There are more rumors than concrete facts around the woman who holds the reins of Demorra's underworld: She was born after a union between a man and the forked-tongue god Salsiti. Venom is said to run through her veins instead of blood. She kills any who displease her with a tasteless poison that she can make materialize into any liquid.

Even the city's empress, high in her palace, has an advisor sip from her glass before she indulges herself of any of her vintage wines.

Eru Farr, Snake of Demorra

Legendary Creature -- Human Warlock (M)
Whenever a creature deals combat damage to you, you gain that many poison counters.
Whenever Eru Farr, Snake of Demorra deals combat damage to a player, you lose all poison counters and that player gains that many poison counters.
2/2

I don't even know what to think about this one. Just sort of an experiment.

A being of murky but cursed origins, Valkoth uses his vampiric wiles to aid in his mission of corrupting wayward mortals. Even so, he cares little for the souls of those he binds with his infernal bargains. His only concern is that they are left with enough blood to sign the pact with after he sates his appetite.

Valkoth, Sanguine Baron

Legendary Creature -- Demon Vampire (M)
Flying, lifelink
If you would sacrifice a creature to cast a spell or activate an ability, you may pay 3 life instead.
"My services can be bought with but one kind of currency."
3/3

I did a quick Scryfall search for black cards with "Sacrifice a creature" costs and I didn't find anything too broken.

Sometimes it's fun to make cards for canon characters that never got one!

Ashnod the Uncaring

Legendary Creature -- Human Articifer (R)
, Sacrifice another nonartifact creature: Return target artifact creature card from your graveyard to the battlefield. Activate this ability only any time you could cast a sorcery.
"Your true potential is trapped behind flesh and blood, waiting for me to unlock it."
3/3

Ooo, nice! The apprentices were my favorite characters of The Brother's War. I had her pegged as fully , but as with her mentor one could make the case for any Grixis combination with

(*artificer)

My knowledge of Ashnod is limited to her MTG Salvation article and her coupon, so I could be off the mark. Mechanically, the card was inspired by Ashnod's Altar and Ashnod's Transmogrant. The blue is mostly just there for the card's connection to artifacts and to make her a better commander. The card could probably just be mono-black with minimal issues.

Haven't posted a goblin in a while.

Goblin Interrogator

Creature -- Goblin Rogue (R)
At the beginning of each opponent’s upkeep, draw a card unless that opponent has Goblin Interrogator deal 2 damage to them.
Whatever secrets his captives spill only briefly interrupt the more interesting sounds they tend to make.
2/3

I posted this in a razorborne contest two years ago and liked it, so a repost is in order.

Undercity Informant

Creature -- Human Rogue (R)
Undercity Informant enters the battlefield under the control of an opponent of your choice.
Undercity Informant attacks each combat if able and attacks its owner if able.
Whenever Undercity Informant deals damage to a player, that player draws a card.
1/3

Funneling spellwork through a goblin's brain tends to result in erratic but highly fascinating results. Kizzick quickly attracted the Firemind's attention simply by being able to repeatedly survive the process.

Kizzik, Firemind's Favored

Legendary Creature -- Goblin Wizard (R)
, Exile an instant or sorcery spell you control: Search your library for an instant or sorcery card with mana value equal to 1 plus the exiled spell's mana value and cast it without paying its mana cost, then shuffle.
"More, more, more!"
4/2

Prime Speaker Vannifar is my favorite Commander of all time. If this one existed, it would be the only deck I'd ever build.