Possible Clues:

• Diabolical food with noxious filling
• Fiendish
• Diabolical meal causing misfortune inside
• Take lead from 15 across - it is hot and the sort of behaviour you'd expect from 26 across
• He's livid, agitated yet mischievous
• Very sinful, like a spicy meal?
• Tricky sort of behaviour you'd expect from 26 across
• Very tricky
• Good-looking person bad within, like Screwtape