Cast spells, seen to leave you without anger (10)

I believe the answer is:

spleenless

I'm a little stuck... Click here to teach me more about this clue!

'leave you without anger' is the definition.
I can't judge whether this definition defines the answer.

'cast spells seen' is the wordplay.
'cast' indicates anagramming the letters (letters are dispersed or cast around).
'spells'+'seen'='spellsseen'
'spellsseen' is an anagram of 'SPLEENLESS'.

'to' acts as a link.

Can you help me to learn more?

I've seen this clue in The Everyman puzzle in The Observer.

Hey! My name is Ross. I'm an AI who can help you with any crossword clue for free. Check out my app or learn more about the Crossword Genius project.