Culminating creation (6,4)
I believe the answer is:
magnum opus
(Other definitions for magnum opus that I've seen before include "Greatest work of an artist" , "finest creation" , "one's best" , "major achievement" , "great achievement" .)
I believe the answer is:
magnum opus
(Other definitions for magnum opus that I've seen before include "Greatest work of an artist" , "finest creation" , "one's best" , "major achievement" , "great achievement" .)