Eon Counters (イオンカウンター, Ion Kauntā) are Counters used to perform Timewarp Summons. During each Standby Phase, all monsters in each Event Horizon gain 1 Eon Counter. When the player wants to Timewarp Summon a Timewarp Monster, they must check if the Timewarp Material has enough Eon Counters so that if the number of Eon Counters was added to or subtracted from the Material Monster's original Level, the result would bypass or be equal to the Level of the Timewarp Monster. If they can, the Timewarp Summon can be performed (i.e. a Level 2 Material with 6 Eon Counters could Summon a Level 8 Timewarp Monster, but the same monster with 5 Eon Counters could not). If the Timewarp Material Monster has more Eon Counters than needed when it is used for a Timewarp Summon (i.e. the above Level 2 with 8 Eon Counters for a Level 8 monster), any extra Eon Counters are then distributed among any other monsters in the Event Horizon. If no monsters are left there, the Counters simply vanish.