Azed (Last 4)
6a Group talk, activity dissecting pictures etc (5) AR _ _ T
8d Almost all the waste turns up slippery in parts (4) _ LI _
(Please note that the 3rd letter of 6a is the first letter of 8d)
18d I’m full of malice, e.g. on first day back at work, not third? (7) _SM_ DA _
Asmodeus was full of malice, so I presume it is a derivative. Asmoday = as (for example)
+ Mo(n)day (first day back at work, not third), but I cannot find Asmoday!
33 Once given the heave-ho, yen to stick around ay rejected (5) _ _ OST
(YHOST fits the parsing if there is such a word! Y(en) + Ho + ST(ay))
(Please note that the last letter of 18d is the first letter of 33a