More changes put around by ruler (7)
I believe the answer is:
emperor
'ruler' is the definition.
(I've seen this before)
'more changes put around by' is the wordplay.
'changes' indicates anagramming the letters.
'put around' means one lot of letters goes inside another.
'by' becomes 'per' (**).
'more' with letters rearranged gives 'emor'.
'emor' enclosing 'per' is 'EMPEROR'.
(Other definitions for emperor that I've seen before include "Ruler - penguin - size of paper" , "Absolute ruler" , "Large richly coloured butterfly" , "Ancient Roman ruler" , "Napoleon Bonaparte, for instance" .)