So I just got a PeroPero Coliseum Ticket for a Mission reward and I looked and saw I still have some left over from the event that I didn't get to use. However, the game said they would expire/disappear after the event ended. So why do I still have them? Will I be able to use these when the event comes around again, or should I quickly use them at Kurito's Nest if they are going to disappear soon?