Urobutcher? Isn't he all about blood and guts?
I chose that idea because I wanted very human problems presented in inhumane ways.
Zangetsu is driven to Helheim because even though he has a high position within the Sarashikis he'd be bound by their rules, which includes not allowing him to find out about his real mother, his real father. He tries to talk to Tatenashi about this but Tate either acts like she doesn't hear him or she breaks down. She's still traumatized about the event and is subconsciously locking away the memory and ignoring stimuli that remind her of such.
So each one suffers because of the other's suffering.