Both of them have fought demons for a long time to get to where they are now. Birds of a feather.

Each of us have our own strengths and weaknesses. My best subjects are English and Maths, my worst is Geography and History.

Correct. Hence I'm just stating the possibilities, I did not guarantee nor state whether the person in the room is the assailant or not, brother or not, I simply stated the ODDS of that person being the brother.

Also, usually people use twirled cloth (white ones are commonplace) instead of rope as buying one is more than enough to rouse suspicion unless you're related to construction.

Possible clause. But the major point of the lines were the following words:
"since... bullied in elementary school... holed up in his room for over 20 years... passing notes for 20 years... first time in 20 years, he was a fully grown man."

Let's Google and process the information one by one:
- Elementary school age ranges from 5 to 13 (13 is quite a stretch for elementary students, but that's what Google says).
- 20 years from then would be 25 to 33 years old with possibly only elementary level knowledge of words if he has no computer.
- Google says 18 is a grown man's age. But by the norm and social standards, any age less than 30 is still considered a YOUTH, not a fully grown man.
- By the second point, home tutor is very likely out of the question since communication is only done by note. So if there's no computer, and with only elementary level knowledge, how would he know the word "assailant"?

The odds and probability, based on the 4th point that the person behind the door being her brother is 1/2 (he has computer for learning) multiplied by 4/9 (brother's age range at 30, 31, 32 or 33, and not 25, 26, 27, 28 and 29), is only 4/18 aka 22% out of 100%. Not saying that there's no chance, but the odds are 78 to 22 that he's not the brother.

Damn! Even I can't fan off the flaming burns you gave there!

Yes, Master Gu is a SCUMLORD but he is no scumbag nor trash, like these arrogant MCs or that loser from Rental Girlfriend.

It will if it hadn't. Imagine spending your entire life's effort for someone who has no regard for your contributions and worth, and ironically reasoned and spared by the one who's supposed to be your enemy.

Its only ruthless when if the pet was weaker than you... which in this case, not at all (Goguma's original level was way higher than the MC's). So I don't really see the ruthless part.

Nope, it wasn't ruthlessness, he got careless. Especially when he was that low on mana and stamina, using Goguma was just an instinct reflex.

Damn. MC got Kill Secured.

Hmm. Works like Disqus. Only difference being that I have other platforms that uses Disqus, particularly anime platforms, so I'd probably find another manga platform that uses Disqus.

It'll be harder for me to engage with others, as I'm unfamiliar with how the notification system works here.

If he lost his sense of self, he'd b*ng her already, why stop at just fingering?

I see. Well, fine by me either way, though I'm very unfamiliar with this system and not sure how I engage those who debated or replied me of sorts.