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'.
“I want to share my life with you, and that means today, and the future, and all of my past. If you want it if you want me.” ... From becomingfoxes ... alexander 'alec' lightwood, the mortal instruments, little one, blueberry, max lightwood - bane