LOL. This story is so insane and so dumb, yet the hyperviolence and endless training growth make it somewhat absorbing, but I guess the fascinating thing is mostly in how obnoxious and yet self-righteous an a-hole the MC can be.
Like most of these kinds of novels with near-infinite magical increases in strength/speed/resistance, the MC has a naturally concealed power (super abilities, etc.), so he looks fairly weak just based on his visible power level, hence he can defeat much more powerful-seeming people - but not only that: it should also be obvious that since most people judge others based on visible power, then the MC is going to be underestimated and treated accordingly.
The MC could coldly take advantage of this to gain a considerable boost in survivability by playing it cool and keeping all his power super secret ('cos normally others will just freaking steal it or murder him before he gets too dangerous), but instead, like a victimized child who desperately needs constant validation, he runs around breaking people's teeth and whatnot, to 'save face' and show how he's the strongest - graaaaah!
The MC does not care about being strategically wise and he deeply pays for it:
At one point he makes it as an inner-court disciple, and rather than just avoid confrontation and play things reasonably smart, he immediately antagonizes the most powerful disciple of the place, and that sociopath later decides to have the MC's entire clan murdered.
So again and again, you see the MC go through hardships mainly because he is such an obnoxious, abrasive, over-the-top guy, surrounded by other self-absorbed monsters just like himself.
And you can't even sympathize with him for losing his family, 'cos just a couple chapters earlier the MC himself had been committing genocide on another clan/family, all without sufficient justification (clearly).
When the MC's brother later gets crippled by some artificial-bad-guy, it happens after the MC himself had crippled HUNDREDS of young people for having simply injured (NOT crippled) some of his family (and of course, the main reason the MC's family was being victimized was because of the MC's abrasiveness).
So time and again, you get to see the MC suffer the consequences of his ill-advised actions, and also time and again you see the MC do all the worst things possible to his enemies, without appropriate provocation, so when you see the MC's own clan suffer similar mistreatment later on, it simply feels like just deserts (karma).
Anyhow, this LN portrays the fantasy of 'what if' you could simply be in conflict with nearly everyone and then end up prevailing over all of them - the trail of broken teeth, crippled youths, tortured, maimed and savaged victims is staggering and all the gratuitous conflict starts to make sense: EVERYONE needs to feel the MC's power and be either completely cowed by it or obliterated.
However, the moronic MC can only achieve this with the unforeseeable help of some OP ppl (because he is IN FACT far too weak and dumb to be doing what he is doing), and it then frankly never seems believable whenever you see any established power take a friendly fancy to an out-of-control a-hole like the MC - what 'nice' master would want a terminally dumb sociopath for a disciple? So the MC still gets key social support in spite of being exactly the kind of person no one would normally ever help out.
So as such, I would actually far prefer this LN if the MC actually had the cunning required to be a complete and total a-hole, end up all alone (which is actually fine, logically speaking, 'cos who wants to be with people that they hate?), and then win over everyone who gets in his way in spite of all that - THAT would be pretty cool, but instead we get to see the MC get showered with affection and presents by sudden mentors and other such improbable happenings.
And later on, the lazy author doesn't even bother to explain (or have a reason) for why the MC wins in his fights. It is very strange: MC is at over 10x less power level than his opponent and is using a not so special skill at the time, yet when each protagonist's spells impact one another, the MC ends up on top, to the complete bafflement of the crowd AND OF THE READERS.
But therein lies the problem with these near-infinite growth worlds: even if the MC is better than his latest madly powerful opponent, he is still thousands (millions, billions, etc.) of times weaker than the 'true powers' of that world, so for most of the story (as an adult) he's going to need to hustle to find himself a 'daddy' to look after him...