Quote Originally Posted by HydroKirby View Post
Here's an update. The devs intend to have the Nidhogg 1st half and 2nd half fights be accessible after this event in some way.

For the 1st half, the wave battles, they'll be focusing on how supports work and the rewards. They want it to be more enjoyable.

For the 2nd half, the maze stages, you'll be able to challenge the Core stage again. They're also looking into allowing people to challenge it as often as they want.

For the wares, the things without an expiration date are going to be just like the Danchou/Commander Tickets. They will never expire. Instead, they'll have a batch added to them occasionally.

Source and link:
[+] Spoiler








Makes sense if you know that some items (ancient Ampies & Flower Ribbons) are only accessible via this event. And since this is a one time only event, anyone that joins after the 5th of March or just started around this event won't be able to get these things nor will they be able to ever face Nidhogg.