look, dude, it’s better than your crotch
To answer your question about copyright infringement- Toby may have utilized and gave you the option in a game to choose between violence and non-violence, but that choice is hardly a new concept. In fact, it is one of the oldest, as far as humans go. For instance, Beyond: Two Souls repeatedly gives you the option to make people's lives hell or leave them alone. Provided that you do not downright copy the "Mercy" and "Fight" system, you should be perfectly okay.