Extraordinary as Grail held -- by him? (3,7)
I believe the answer is:
sir galahad
'him?' is the definition.
I don't know anything about this answer so I can't tell whether this works.
'extraordinary as grail held' is the wordplay.
'extraordinary' indicates anagramming the letters.
'held' becomes 'had' ('have' can be a synonym of 'hold').
'as'+'grail'='asgrail'
'asgrail' is an anagram of 'sirgala'.
'sirgala'+'had'='SIR GALAHAD'
'by' acts as a link.
Can you help me to learn more?
(Other definitions for sir galahad that I've seen before include "painting by symbolist Watts" , "paragon of virtue" .)