I'm struggling with the last few clues and haven't got the theme yet - any help appreciated.
14a) Brilliant 1 set apart Scots miser (4)
16a) Against malaria it's uncertain (5)
5d) Cold part of NE Asia head off for
warmer parts (6) ????IA
7d) The King's female displays volume in
highest pitch (singing) (4) ????
13d) Hat - a caballero might wear it (4)
25d) There's TNT in this mostly old match's cavity - not HE (6) ?M??O?
23d) Some rioter's holding a club (4) ??R?