16d- diabolical torment under second bombardment (9) - S?E?L????
26ac - figure arresting good judge (5) - O???? - opine? i see the number one, but not how pi defines good
21d- though grey, lead absent (6) - ?N???? - 4th letter is E if opine is correct
28ac- as may be a dres? (8) - ?A?K???? - dres really is how it is spelt in the clue, but I have no idea what it means or is