Imagine:
Magnus chase realizing that yes he can talk to annabeth about all the stuff that happened to him bc she also knows abt the gods and that myths are real.
But also him being jealous that Percy was able to turn down immortality but not him. He never had a chance to say no. He never learned abt all that stuff before his death.
But also Annabeth's point of view, that her little cousin is so used to die on a daily basis at valhalla that the thought doesn't really scare him anymore. Or plainly that magnus dies at valhalla daily at all.
The talkes they both have:
Annabeth: I tell u last week percy fell from the lava wall and burned his hand so bad he had to go to the apollo cabin to get ambrosia for it to heal. Will was not happy with him.
Magnus: I am so happy i am fire resistant bc of my dad! That must have hurt a lot... The most that happened last week for me was getting crushed to death and once breaking my neck. I can tell u even after waking up again in my bad my neck hurt for days!
Annabeth: ...
Magnus: oh and i found another really good falafel place but don't tell amir!
Annabeth: sometimes i forget that u die on a daily basis...
Magnus with a straight face: u get used to it