Joined in action with mystical characters, those perhaps responsible for movement? (6,6)

'those perhaps responsible for movement?' is the definition.
(food which may encourage bowel movements)

'joined in action with mystical characters' is the wordplay.
'joined' becomes 'wed'.
'in' indicates putting letters inside.
'action' becomes 'step' (step is a kind of action).
'with' means one lot of letters go next to another.
'mystical characters' becomes 'runes'.
'wed' placed inside 'step' is 'stewedp'.
'stewedp'+'runes'='STEWED PRUNES'