Ahoy hoy,
I'm a 30 year old British guy with too much time on his hands. I have ran many one off games in different systems as well as spent a year running a pathfinder campaign and then almost two years running a Call of Cthulhu campaign. All in person though, GM'ing in Roll20 is very new to me and will need a bit of a learning curve.
I love running though, I love creating worlds and watching players interact with them. I'm very much a GM who wins when the players win and loses when they lose, but at the same time I want the players to feel challenged as it improves the feeling they get when they overcome it. So while I won't be actively trying to fuck with the players, I also am unlikely to go easy on you.
I'm also very fond of realism in games and will strive to do so as much as the setting and mechanics allow.
When it comes to Mature games I run nothing is off limits unless the players expressively ask me not to include it. So it is possible you will encounter things such as racism, grizzly murder, rape, and a whole lot of other unsettling things. Please remember this is a game and anything that happens is because it is necessary to the story, and having a good story that makes people feel all kinds of emotions is important to me.