I asked this question to Patreon, and they responded to me recently. Apparently, if the MC enjoys what he sees, Patreon bans it; if he doesn't enjoy it, they don't.
To clarify - If the content is meant for the sexual gratification of the player, Patreon bans it; if it isn't, they don't. What the fictional character feels does not matter.
For example, a rapist in a game enjoys raping - whether or not they are the MC. However, the context of the narrative determines if the author is attempting to titillate the player in a sexual way. See the movie "The Accused" about a gang rape in New Bedford, Massachusetts and the prosecution of the rapists. The rapists enjoyed themselves. However, something like that would less likely be banned from Patreon because the intent and context isn't for viewer sexual gratification.