The bosses in Elden Ring Nightreign are already pretty tough. The first Everdark Sovereign you can fight is a new version of Adel, Baron of the Night, aka Gaping Jaw. When you beat an Everdark Sovereign, you’ll get “Sovereign Sigils,” which you can exchange for “special Relics and other items.”There are a couple caveats to be aware of. And Everdark Sovereigns will only be available for a limited time — the upgraded Gaping Jaw, for example, will stick around until June 25th at 8:59 PM ET. Other Everdark bosses will be added “at a later date.” Based on the blog post, it seems like Everdark variations will eventually return after they’ve disappeared.