Quote Originally Posted by blacksaber View Post
Conversation between two Aigis devs.

"Hey, lets put in dark knight orbs."
"But we haven't implemented Yurina."
"Tee Hee. I know."
"I love that idea. Lets go with it."
The dark knight orbs are used to awaken the vampire princess class, which had awakening implemented in the recent update. This does however cause the odd situation where awakening orbs are available that are only useful for a single one off event unit that requires another awakening orb type as well, while the class the orb is named for is yet to be available.