They were indeed tethered, souls entwined, unable to exist without each other, even though both of them had tried so hard at different times to sever that tie. Hannibal knew Will's actions on the cliff had been a recognition of that fact, an acknowledgement, a surrender. He had vied for them to die together, but fate had apparently intervened, as it had so many times before. And now they were here, together. Whether alive or dead, they would exist together.
When Will closed the space between them and lowered his forehead to Hannibal's shoulders, Hannibal wrapped his arms around him, drawing him close, one hand going up to gently cradle the back of his head. He turned his own head slightly, pressing a kiss to Will's temple, before closing his eyes and just holding Will.