Quote from Shadowhunters 2x08 │ Jace Wayland (about Alec): Look, I’ll make this simple, okay? I’m never gonna let anyone hurt him. Magnus Bane: Then we have that in common. You think I’d invite Maryse Lightwood to my home for just anyone?
We don't often use the word 'bane' any longer and when we do it is likely to be as part of 'the bane of my/his/her life'. This is usually uttered as a complaint against a not very serious threat, for example, a gardener might complain "those slugs are the bane of my life". Baneful threats weren't always so casual. 'Bane' is a very ancient word, recorded in the Old English Chronicles as early as circa 800, meaning 'murderer'.