Scandinavian of manner so strange (8)
I believe the answer is:
norseman
'scandinavian' is the definition.
(Norsemen were ancient Scandinavians)
'manner so strange' is the wordplay.
'strange' is an anagram indicator.
'manner'+'so'='mannerso'
'mannerso' is an anagram of 'NORSEMAN'.
'of' acts as a link.
(Other definitions for norseman that I've seen before include "A viking, perhaps" , "one attacking north-east?" , "invader" , "Scandinavian" .)