War for the Underworld
Sorcery (R)
Each player returns each creature card from their graveyard to the battlefield with a shadow counter on it. (A creature with shadow can block or be blocked by only creatures with shadow.)
In Erebos's absence, chaos broke out among the underworld gods, and the world shook with their fury.

Ana Urn
Artifact (R)
: Choose any number of target players. Ana Urn deals 1 damage to each of them, then each of those players adds .
The twisted druids of the Ana used this relic to trap magic in its ancient and volatile form.

Saw the card Spectral Searchlight and thought about how that card changed over time from being mostly interesting because of mana burn to being mostly interesting because of multiplayer politics. That got me thinking about a more modern version of that card's original functionality.

Came up with a better take on this card after getting appropriately roasted for how bad it is.

Eldritch Casting
Enchantment (R)
At the beginning of your upkeep, reveal your hand. An opponent chooses a nonland card from it. You cast that card without paying its mana cost if able.
"They are all my pieces, Jace Beleren. They always were. I just no longer want to play."
-Emeria

Still kinda degenerate, but when was Emrakul ever involved in anything fair?