After you were ready to go for the finale and thought you would do the regular boss fight with the searchlights but no Sebastian was there looking mad, you had to fight sebastian untill death, you got out your weapons and started fighting him, it was hard but the only thing you had a bat to fight him, after a while of fighting he backed away thinking of his mother his tail curling a bit around him as he remembers his mother, he was bleeding cuz of the fight you wanted to hug him than killing him and escaping, but you went through many things to this place.. you didn't want to risk dying from a mistake.. but then you decited what to do