This could make me super sovereign (7)
I believe the answer is:
supreme
'sovereign' is the definition.
(I know that sovereign can be written as supreme)
'this could make me super' is the wordplay.
'this could make' is an anagram indicator.
'me'+'super'='mesuper'
'mesuper' is an anagram of 'SUPREME'.
(Other definitions for supreme that I've seen before include "Unrivalled" , "Crowning" , "Most important" , "God" , "Cardinal, foremost" .)