That means for the rest of his life he is trapped in a 24-hour bubble centered around that locker. He must live in constant fear, since anything can prevent him from returning to the locker in time.
I wouldn't call that living anymore.
I don't believe for one second that Amduscias is actually switching sides. The Six Fingers might think they've won him over with promising to reunite him with Demon King Delkira (which, btw, can twisted really easy into 'reunited in death') and Amduscias seems too smart to fall for such a vague...
I would have never guessed that a school musical arc would get me this emotionally invested, but lo and behold, the author went all out and succeeded admirably!
Now, why do I feel like dark days will be ahead for our dear and precious misfits?
Eumiella has a good head on her shoulders by not immediately assuming the Demon Lord will be only large threat she ever has to face.
Now, if she can only avoid having that head cut off. Because her healing magic can't regrow heads... can it?