What are souled out crytals?

InfiniteAbe17

I had extra keys ad they converted into skeleton keys and say i can turn them into souled out crystals in a store but i cant find it, is that something thats gonna be released or whats up with that?

Fluffy_paws

its in the crystals tab. chance at 4* 3* shards t4cc frags, gold

Meebleton

A mediocre pun