The Necromancer is amassing troops like crazy in the apocalypse

I have read the novel till the current RAW chapter. It was good when it started out, you had an MC who for some reason gets transported to a pre-Victorian world and can travel back and forth to the modern day with the help of a key. After his first journey into the world, he gets back only to realise the modern world has somehow become zombie infested, he has the profession of Necromancer obtained in the other world and uses it to gain foothold in both worlds. Fantastic setting. in execution though, he starts of well, builds healthy relationship with his co-workers and seemed all around nice bloke, but then he goes off with incredible harem route, he has 1 lover from his 1st town, 3 admirers who like him but not had any romance with him yet. moves to another city and gains 1 more servant with contract whom he impregnates later on, 2 beastwomen servants who later became his maids/bedwarmers, moves to another city and gains a wood elf girl as mistress, 3 more ladies who like him platonically. on the modern world side he has already has 2 ladies by his side with whom he had romance with . like the f.. is wrong with this dude. more than 70% of the chapter content will be filled with him either flirting with his harem or grinding exp with skeletons. the actual plot is only about 10% avg, rest 20% is useless dialogue. Author has built a good world but failed to populate it with characters and stories that are interesting, for example MC gets in conflict with this group of secret society. they constantly trying to send people to hunt MC even when there is no benefit to do so and this secret society has so much pill that there are even high ranking members of association and countries are part of it but somehow they fail to realise that MC is hard nut to crack but he is not going after them at all so why bother muddying the water and get their members found out? Ultimately it had potential but then became a popcorn novel.