The sister is gross and annoying. I don't care that they aren't blood related you shouldn't be all obsessed with your brother its gross and weird. If she's included in his harem I'm dropping this story. The way to power on the battle golems is a classic Eechi moment and I get that he needed to explore the city for clues but is he a Buddha or something? If a real guy was in that scenario it probably would of been a full sex scene. Seriously instead of walking around with a boner and blue balls just finish what you started especially since they were definitely designed with that function in mind, I mean their power bottom is by their cervix. If you are going to write a pervy story just commit to it otherwise its boring and typical isekai neet gets reincarnated.
ISEKAI CHEAT KAITAKUKI