What can the reader infer to be true of roderick usher's character based on how his letter to the narrator is described?

Similarly as in about each other short story by Edgar Allan Poe, "The Fall of the House of Usher" is intended to rotate around an invading nearness of malevolence. Something fiendish lives and hides inside the house itself and in addition inside the group of Usher. A huge piece of this fiendishness is inbreeding.

Roderick Usher is struggling both mentally and physically