Board Thread:General Discussion/@comment-190.225.153.23-20140408001952/@comment-70.24.149.98-20140408004915

Wait do you mean whether it's possible to get the event archwitches when the event is over? If so, no, you can't get them anymore, not even in premium summon.

Unless nubee decides to make an event like the one where they brought back some past archwitches, then there's a chance you can get those archwitches again.