hannibal/will magic au that has will as a spellcaster who has so much potential but is afraid of losing himself, and hannibal as a caster who is completely comfortable and in control of his magic which specializes in blood and possession (as well as other more run of the mill magicks, child's play to someone of hannibal's prowess), who has wrecked careful, precise havoc around the world, only leaving the barest shreds of evidence behind, and only so things stay interesting
hannibal coming across will and being able to sense the untapped power, running a little drunk on it; hellbent on getting will to embrace it, wanting to crack will's powers and his ribs open alike, let blood and magick spew out of him like a geyser
seducing will, tapping more and more magick out of him day after day, showing him just how much he's really capable of
staging an attack on his person once will is fully ensnared to provoke will into really using his powers