It's the Niddhoggr event.
Half of it is based on a slightly different versions of boss battles (you can challenge them anytime, for any amount of raid points) and the other has a series of 4 stages on which girls with different types of battle skills perform better.
In a big nutshell.
Name: Volarmis
DMM ID: 317568967
The pest on the raid boss button? It's Nidhogg. But there is no Nidhogg event right now. Weird. It should be a kind of bug if you see that right now. And it's not supposed to be over the raidboss button but replace the raidboss button...
Hello. Long time player from nutaku trying to make the switch to dmm. Everytime I try to register my profile for dmm games I get this error message, translated to english:
We are sorry.
The site is very crowded just now.
We apologize for your inconvenience, but please try it for a while. If your time is not improved, please contact our Support Center.
In games.dmm.com, theres should be language select box, change it to JP and redo the register profile (for some reason the redirect from dmm to games.dmm change it to /en even tho all language still in jp). After doing that, it magically passed step 1 of profile registration.
A real flower knight girl
https://twitter.com/i/status/1126824108400857089