There were many things that came to fruition on that clifftop, things that he had wished for Will, wished for them, for a long time. Will coming into his own as the beautiful, deadly creature that Hannibal knew him to be, able at last to see the beauty in blood in the moonlight, was the most monumental and important, of course, but nearer to Hannibal's broken and bleeding heart was that embrace, their arms around each other as they gasped and bled, love clear in how they leaned on each other, nuzzled each other, so very close to a kiss...before Will used that embrace for one final betrayal.
The fact that Will was now in Hannibal's arms, holding on tight, made clear that the embrace was not a false one designed only to take advantage of an opportunity to end Hannibal once and for all. Hannibal felt Will was truly able to acknowledge the emotion between them, just as he was able to acknowledge his own true nature.
He gently stroked Will's hair, and again kissed his temple.