Sure, I could expand this with a second choice/outcome in which they do survive, since it can otherwise be quite startling.
There will be a number of bad endings throughout the game, but they will always loop back to the previous choice so that players don't have to worry about losing progress. My goal with this is that by taking invulnerability away from the protagonist, there will be more of a sense of danger and suspense during fights and other heated moments.
Of course, these scenes will be added sparingly, as having to repeatedly rewind would lead to frustration.
The succubus heroine is capable of mind control (i.e. forcing the target to do her bidding) and uses it at a key moment early in the story. Depending on how far the protagonist corrupts her, it will be possible for her to use various forms of mind control at other points in the future.