"A simp" - how so?
"A creep" - a bit, though see next point
"Deus ex machina sex helper power" - nope, that's not a deus ex machina, that's the setting of the story, so a premise. Which also works on the MC, so the creep is somewhat justified. (You're of course perfectly okay in not liking the premise)
"Hateful character" - how so? And what does that have to do with anything you mentioned before?
simp : "you are part of OUR family"???mc just got this female japanase in the house and already ready to go to war with his female sister assassin,simp detected;alas its a porn game so of course all females need to be collected but the story there could have been better
creep : can understand this one cuz its caused by the fog?dunno tough
deux ex: there is no character development nor a story one.the story is going forward just by the op deus ex sex helper power.
mc not seduce neither is seduced by the harem members,all is done by this power.
switch out this mc and all the harem members with new different mc and new different harem members and the story would have been exactly the same.
hateful character: the mc shows 0 personality through the game except when he acts like a 12 years old japanse isekai character,like when he confronts the old lady about the spider letter.
harem members are no better:they show a bit of personality in the first levels of interactions(not really tough: just the shy,dominant,ara ara tropes;superficial level too) and then they turn into machine sex lust personas.
so when u got to the sex scenes u are not watching the culmination of a story between 2 characters but simply 2 robots who do sex things,thats boring as hell.
alas man of the house was 1000x times better.