Duping punisher from arena crystal

Greekhit

Duping a max sig 3*/4* punisher from arena crystal don't award extra shards or max sig stone. Is that intended or is some kind of bug? It just doesn't seem fair. Do someone know why or a moderator clarify?

will-o-wisp

It is intended due to it's nature.
Same thing with Unstoppable Colossus