I think we all need to take a minute to think about how evil Derek had the potential to become. Villains always have a trigger. Derek ignored his and became a hero.
The thing about Mary, is that she has completely changed my life around. Changed everything. But, for the record, over the last few years there are two people who have done that, and the other one is… a complete dickhead.
Because, sometimes, things happen to people and they’re not equipped to deal with them.