Doom counter

Doom counters are a type of counter introduced in Antiquities. They act as markers for various forms of future thematic doom, some sort of damage or destruction to players or permanents. 
==Description==
Despair counters first appeared on <c>Armageddon Clock</c> in Antiquities as unnamed counters which were later given errata to be Doom counters. It was an artifact that would build up a Doom counter each upkeep and then deal damage to each player equal to the number of counters on it during each draw step. Each player could also activate its ability to remove a Doom counter for a mana cost.
The counters appeared once again on <c>Eye of Doom</c> in Commander 2013. It is an artifact that allows each player to place a Doom counter on a non-land permanent when it enters the battlefield. It can then be sacrificed to destroy all permanents with a Doom counter on them.
Hour of Devastation also saw the return of Doom counters with <c>Imminent Doom</c> which was an enchantment that enters the battlefield with one on it. It would then deal damage to an opponent whenever the player plays a spell with a mana cost equal to the number of Doom counters alongside gaining another. 
The counter appeared in Commander 2020 on <c>Lavabrink Floodgates</c> which gave the choice of adding or removing a Doom counter each upkeep. If it builds up to 3 Doom counters then the artifact is sacrificed and deals 6 damage to each creature. 
===Acorn===
In the Acorn set Unstable, the counter was referenced on <c>Baron Von Count</c> which enters the battlefield with a Doom counter on the "5" in its art. They then act as a countdown where the counter is moved down a number whenever the player casts a spell containing the marked number on its mana cost, text box, power, or toughness. When the Doom counter hits "1", the target player is destroyed and it moves back to "5".
==Trivia==
*In Magic Online, the counter is colored blue as its considered a neutral effect. It shares an icon with Corruption, Death, Despair, Mannequin, Paralyzation, Petrification and Soul counters.
==References==