Strangelybrown, the answer to 5a is PLUTOCRAT, but the parsing is very convoluted. DIVES (pronounced DY-VEES) is Latin for "a rich man", and is often used in the context of "Dives and Lazarus". This provides the definition (PLUTOCRAT). The underworld figure is PLUTO. Runs is R (as in cricket), "guarded by" (ie surrounded by) CAT (animal). Thus: PLUTO C(R)AT.
Hope this helps.