The plot is great, but it ruined in chapter 5 because of MC's strategy to save him... I hope there is explanation about this in next chapter. It just that scene is not necessary yet. But still the CG, character, BG, music are immaculate.
Sex releases Endorphine. Endorphine reduce pain.
The only thing missing is a clear statement that Brute was in such a pain that even painkillers aren't sufficient enough to save his Life.