Dynamis (神域 or デュナミス Dyunamisu) is the place where Z/X Extra and the upper part of Z/X Overboost cards are placed. In the story, it is the name of the place where the Dingir lived.
Dynamis is a separate deck from the player's own deck. Player may put up to 10 Z/X Extra and up to 4 upper part of Z/X Overboost cards in their own Dynamis for a total of 14 cards. The rule that states that you may only have up to 4 cards with the same name in a deck still applies to Dynamis. During the game, Dynamis is put into the Dynamis Zone in face-down position. However, a player is allowed to look at the contents of their own Dynamis anytime during the game. All face-up cards in Dynamis can be seen by all player as well.
Z/X Encyclopedia Entry
The place where the gods lived. It is isolated from the present world, and they can't interfere with each other. However, the conflict of the five worlds caused distortion in the time and space... and the Dingir finally descended.
At the same time as the advent of the Dingir, different structures and landscapes rises above the sky over the Black Points. Because of that, there is a rumor flying around some Z/X users that the Black Point is the so-called product of Dingir created with technologies from the Dynamis. However, the physicist specialized in many-worlds interpretation, Carl Wyvern, who has not yet encountered the Dingir is skeptical about the rumor.