Svengali-like figure arty types installed (8)
I believe the answer is:
rasputin
'svengali-like figure' is the definition.
(mystic Grigori Rasputin)
'arty types installed' is the wordplay.
'arty types' becomes 'ras' (RAs, members of the Royal Academy of Arts).
'installed' becomes 'putin' (put in can mean to install).
'ras'+'putin'='RASPUTIN'
(Other definitions for rasputin that I've seen before include "Peasant monk" , "Puritans (anag) - Russian monk" , "Mystic who influenced the Romanovs" , "Old courtier" , "Influential adviser" .)