The man, the myth, the legend
Sir Belvedere was born into wealth and power. From the beginning he knew he was destined for greatness, heck, everyone told him so. By his teenage years it became obvious that things might not work out for him quite that way. You see, Sir Belvedere is painfully clueless. Convinced of his own goodness and greatness he has turned into a mockery of everything he thought he stood for.
A young friend by the name of Devin figured this out at a young age. Supplying the brains he was able to turn Sir Belvedere and his brawn away from the path of good and towards The Family.
Devin has moved on, but Sir Belvedere perseveres, knowing in his heart that he is doing good even when asked to do what most folk would consider despicable. The Family provides constant assurance and feedback to him that he needs. Meanwhile, he is happy to guard various adventuring parties on tasks that he cares little about. By protecting these people he is doing good. That is enough.