last one-help please and explanation-nb a single letter in the word play may be superfluous to the solution-thanks
11d very,very good knight left swollen -headed 4 ?A?N vain?
I'm not familiar with this crossword, but Vain sounds right, and I think viagra might be involved. Agravain was the nephew of King Arthur. V=Very, IA = A1 backwards (left) = Very Good... Vain = swollen headed.