A way to describe a minister or his main quality? (3,9)

'his main quality?' is the definition.
I know nothing about this answer so I can't judge whether this works.

'a way to describe a minister' is the wordplay.
I cannot quite understand how this works, but
'way' could be 's' (Compass direction - South) and 's' is present in the answer.
'minister' could be 'rev' (short for reverend) and 'rev' is found within the answer.
This may be the basis of the clue (or it may be nonsense).

'or' is the link.

Can you help me to learn more?