Death crystals are very ancient and very dangerous. The First time Kup saw one was on Vandros Seven. He and his team were being pinned down by heavy fire. A couple of the hot headed young bucks decided to charge.. When they did, they each got shot once by something powered by one of these things.. They just.. shattered. Not exploded, not shot.. just shattered into so many pieces you couldn't even make out who they were. Kup’s team was pinned down for two cycles before they figured out how to get around and flank them from the rear. They never gave it a name.. called it what it was.. a death crystal.
After Kup’s initial encounter with them, they tracked their planet of origin to place called Dread - Kup and a small group of others were tasked to work as black ops to infiltrate and gain intel on the death crystals, As well as any means that existed of counteracting or destroying them. They didn't find out anything. In fact, they got captured. Spent so many cycles there they lost count. Imprisoned. Tortured. Repaired, only to be tortured again. Only one shot presented itself for anyone to get off that rock. Kup was voted to go. He was able get out, and get back. The others stayed behind, knowing what was going to happen to them. When Kup got back, high command debriefed him, and summarily disavowed the other mechs that went with him. The last Kup'd heard, they'd erased all references and records to death crystal in all archives. They figured if no one knew about the death crystals, no one would go looking for them, and no one would use them again.
Kup told them it was a bad idea to do that. Pretending like something exists never works, and it doesn't unmake it. Still.. it's one of those things he wished he never knew about.