Not Always the Hero; Rewritten // (Percy Jackson x Peter Parker)

When Peter was twelve he saw a national manhunt on the news for a boy his age, Percy Jackson.
A year later, they become neighbors and he meets the other boy. They strike up a friendship. A few years after that, Peter becomes Spider-Man. Superpowers can't stop his friend from vanishing unexpectedly though.

or
They are sixteen, it is just barely still summer, and Percy is back not long after the Sleep Incident, looking... good, there's this lightness to him.
Percy and Peter start hanging out more, since their summer is rapidly coming to an end. Percy had decided to try and teach his shy neighbor to skateboard and it went pretty terribly.
Peter starts to trust Percy, starts to seek him out (even contemplates telling him about Spidey).
And then Percy is gone.
and he stays gone.
It's been over a year but Peter would recognize him anywhere. Percy Jackson is standing there knocking at his mother's door.
Like it hasn't been almost two years.
There he is though. Percy Jackson. Alive.

Characters belong to Rick Riordan and Marvel respectively