That's great, though I do feel that the name doesn't quite hit the mark. I think I would rather go for something having to do with "completeness" or "being in equilibrium" for example. As "Infinity" it sure seems finite

Mana Hoard

Enchantment
: Create a tapped Treasure token.

This is quite recent "tech" but yeah.

This was hinted at pretty heavily in the Mystery Booster playtest cards as a mechanic named Ransom: Frogkin Kidnapper.

Hmm, the naming is rather restrictive in that it implies opponent only while the mechanic could be used for yourself. I recall seeing that type of mechanic generally being named like "cache" or "store" though I can only find this "upload" mechanic from "Netropolis" set. also seems too much to me whether it was used for yourself or against opponents.

Qui-Gon Djinn -
Creature - Djinn
Flying, haste
Whenever ~ attacks or blocks, flip a coin. If you lose the flip, sacrifice ~.
6/6

That card has extremely high variance. It might easily hit for 18 damage or 0. Just the swinginess of a single attack swing between 0 and 6 is too much I would say.

While there's a small subset of players that do enjoy these type of effects and the gameplay they facilitate, there's a high number of players, especially 'Spikes', that detest it. It's because of that reason that when these sort of cards are printed by WotC, they tend to be tuned in such a way that they would be very unlikely to see competitive play. Evasive 6/6 with haste for 2, even if it has a 50% chance to die on attack, is still good to not be played competitive.

... that name though

Bear Monk -
Creature
Whenever you cast a spell at sorcery speed, ~ gets +1/+1 until end of turn.
2/2

Posted this somewhere else and then realized it kinda fits here.

Omnipresence
Enchantment (M)
Untap all lands you control during each other player’s untap step.
You may cast spells as though they had flash.

WotC loves printing fixed versions of broken cards. Why not try fixing Prophet of Kruphix?

Overdraft -
Sorcery
Target opponent discards a card. If he doesn’t, you draw two cards.


Courage -
Instant
Put a +1/+1 counter on target attacking creature.
Draw a card.

Here's this card I found on /r/custommagic by /u/IceDiveMTG that fits this thread perfectly, I hope people don't mind me (re)posting it here.

I would make it a non-mythic rare myself, but regardless, it's peculiar that no card with just the simple text of "Destroy all noncreature permanents" doesn't exist yet.

To be fair, "noncreature permanent" includes lands, and the last Armageddon variant was Fall of Thran.

Would be neat to see something like a noncreature, nonland version though

Sweep Away
Sorcery
Destroy all noncreature, nonland permanents.
"This wind is fierce, yes. But it won't move the woods around us, and we aren't so helpless that we can't find shelter therewithin," - Rhys.

How did miss that it also hits lands to this day?

Oh hey, just one month later, look, we have an instant-speed mana dork!

A simple mix of cards like Village Rites, Innocent Blood, Diabolic Edict, and Bone Splinters.

Twirl Away —
Instant (U)
Exile target attacking creature you control, then return it to the battlefield tapped and attacking.
Princess Vanesha would accept no engagements, whether on or off the battlefield.

So if you cast that on a blocked creature you control, it becomes unblockable, right? I think there's a considerable portion of players that are going to find that somewhat unintuitive and especially newer ones are going to be perplexed. It also feels sort of out pie - though you can technically do similar things with protection. It's pretty cool that the creature still gets to avoid spot removal and whatnot if those are cast while it's attacking.

In any case, I can't say I'm surprised as to why that type of card hasn't been printed by WotC already.

Investigating has been limited to mostly bant so far and there are no red cards that do it so it's a pretty easy design space to snoop for some easy expectable designs. There's an urge to slap haste on this but for any standard environment I doubt it needs it.

Predator's Insight

Enchantment -- Aura
Enchant creature
Enchanted creature has "Whenever this creature deals combat damage to a player, draw that many cards."
Let's see curiosity kill this cat.

Exotic Orchard | Reflecting Pool
Fellwar Stone | This

Reflecting Stone —
Artifact (U)
: Add one mana of any type that a land you control could produce.
In it, Martin beheld the world as the world saw itself.