In ce2e2 Mads said that Will was the first person Hannibal saw a future with. Hannibal knew Alana, Bedelia, Randall Tier much before he knew Will but yet he never saw a future with them? Tobias, someone who has a much darker nature than Will and can understand Hannibal because he is a psychopath himself, tried to seduce Hannibal in s1, yet Hannibal didn't see a future with him and declined his efforts. Why do you think he saw a future with Will unlike these other people Hannibal liked?
Sidenote maybe, I don’t think Hannibal liked Tobias at all. Tobias is a compulsive killer. He can’t stop. Meanwhile Hannibal can stop at anytime, he just chooses not to. I think Hannibal can’t respect such an impulsive mind. Again, there is no comparison between all these people, Hannibal likes Will because Will is Will, not because he’s better than Alana or Bedelia. It’s like ice cream flavours, I like butterscotch not because it’s better than vanilla or mint chocolate. I just like the way butterscotch tastes. I can’t then go on to say “I’d like mint chocolate if it had hardened caramel bits in it.” Because it’s absurd to want that.
Why could Hannibal imagine a future with Will? Hannibal is kind of this ideal human being right? He is perfect in every way. He lives up to the human ideals of a god without even trying, and hence he lives in the present. At the final moment on the cliff, he was elated because his mind branched off into a future scenerio. He saw a possibility of having Will’s company. Perhaps because Will willingly killed and so this is a step further into forcing Will to solving his cognitive dissonance, or because he had a literal partner in crime in the scene before and imagined a similar thing happening again.
Then what does Hannibal like about Will? I don’t like to analyse love too deeply. Then I’d have to breakdown Hannibal and Will’s personalities and I don’t want to do that. Simply, I’ll say Hannibal appreciates Will’s bravery and ruthlessness. He also likes his vulnerability and the way he makes sense of the world given the way his mind works the way it does.