It seems these yellow messages gives you Mid Equip seeds directly. That's just a replacement for raid bosses since, for this event, raid bosses are replaced by Nidhogg bosses. I guess. It should be back to normal next week/next event.

And I got my Naes too. Now red Nae has a cute purple Nae little sister.

The event girl is interesting too. I like her more than her sister. Too bad she is just an event girl.