ABANDONED. Invisible/non corporeal prince

[Erin]

Read in the late 80s or early 90s. Red cover, possibly with four retainers, witch, wizard, maid and scary assasin type guy in corners ofcover.

Plot:
Young prince drinks a magic wine that children shouldn't drink which makes his body dissappear - but he regains body parts as his mysterious friends/teachers die while on adventures.

Also has a stirring song about goblin adventures called Penna Pike.

Unfortunately too many of my searches get directed to The Half Blood Prince.

[arratavy]

See if this one fits One for the Morning Glory by John Barnes.

[Kris]

Seconding Tarra's suggestion.

[Kris]

No response, moving to Abandoned folder.

Erin (OP) last posted in the group in July 2019.