I wish to also shill:
The Greatest Estate Developer is about a civil engineer who gets Isekai'd into a novel (as one does in a webcomic) and is granted some magic powers (as often happens in webcomics).
He pretty quickly declares that his goal is to build enough modern amenities (and swindle enough of his neighbors) so that he can retire and relax for the rest of his life.
But, you know, there's giant monsters (because it's a webcomic) and rival dukedoms, and imperial intrigue, and he keeps finding himself in the middle of it all.
There's a lot of comedy, and a ridiculous bromance between him and the novel's main character.
But I'll look into Terror Island and Pixel.