The MC is 99.9% of the time just a reflection of the authors desires of showing off/getting laid anyway, any character they have is not any more constant than what the author thinks matters at the time of writing, they never plan character interactions or personalitys outside "this char should be like a cool me" or "this char should be like that char from that other series I like"
Basically talking about the MC is just talking about the author without admitting what you're actually talking about. Getting confusing or different conclusions from trying to put these unplanned character interactions into a larger whole that was never planned by the author just leads to chance if good or bad according to various readers.
These storys are not books, the authors are not doing them in a planned or professional manner, do not expect characters to have consistant characters and be relatable in any way. Not to mention that they are all super human and can control their bodys and thoughts and souls and whatever flawlessly (other than when author randomly decides they cant) and never have any adjustment or mental issues outside being killers or not killers, being rapists or not rapists, being complete cowards or utterly fearless... They are all extremes, and if they aren't extremes they jump all over the place according to authors mood... Planning is way above these authors grade, paygrade and level of writing competence, even the experienced ones only pen the main plot points if even that.
And don't tell me it's not true with no facts to back it up other than some twitter comment or a "taking a break for planning next volume" crap.