Okay but FE3H except post-time skip Byleth has a waking up period like Sothis where she takes a bunch of really long slightly concerning naps where she keeps waking up and falling back asleep, if slightly shorter next time. (Starring f!Byleth in this post because I always play her)
On one hand, we have many soft moments: Byleth falling asleep on people, trying so hard to stay awake before falling asleep in the war room or something, people worrying for a while that something is wrong before coming to the conclusion that this is okay, she’s getting stronger, she’s just taking her time waking up. There are a few cuddle piles because something about seeing her sleep so peacefully makes it easier for everyone else to sleep.
We have nap queen Byleth who keeps waking up in time to kick the next baddie in the butt before conking out again. She’s asleep everywhere. You turn around and she’s snoring. They found her in the rafters once. They think she might be sleepwalking or something because she’s always there. One time she somehow managed to fall asleep in a caravan that was headed towards the front lines and she woke up long enough to decimate the enemy forces before finding a comfy patch of grass and going back to sleep. Linhardt is extremely jealous. Sometimes she sleep talks in long dead languages and whatever it is she’s saying Seteth clearly knows because he overheard her once and almost fainted. (He won’t say what she said but he has since made a concerted effort to avoid her sleeping since. Flayn thinks it’s funny.)