If you're looking for manga similar to How to Build a Dungeon: Book of the Demon King, you might like these titles.
After he and his entire class die on a field trip, Odamori accepts an offer from a mysterious man to be reincarnated. However his new job turns out to be that of a 'Slavemancer' with the power to dominate the minds of others and turn them into his toys, which he happily takes on. Soon however his evil actions lead to a Princess Knight (who turns out to be one of his previous, more popular classmates) being dispatched to apprehend him. But Odamori of course has something different planned for their reunion.
2 votes
Man has magical powers, man uses said powers to build a harem, man has sex with said harem. That is basic plot for both Himekishi ga Classmate! and Maou no Hajimekata. In classmate the lead was reincarnated, and in Maou, the man just regained his youth through magic.
Lots of sex, impressive harems, and mindbreak in both.
Both stories involve a man using mind control to build a harem of sex slaves, which includes a knight who could be seen as a special threat to oppose/resist his powers.
A young priestess has formed her first adventuring party, but almost immediately they find themselves in distress. It's the Goblin Slayer who comes to their rescue--a man who's dedicated his life to the extermination of all goblins, by any means necessary. And when rumors of his feats begin to circulate, there's no telling who might come calling next...
2 votes
Both take place in fantasy without explicitly game-like mechanics. Both have very dark themes and explicit content, and have powerful characters. Both manga also have monsters and people of various game races in them (ie elves, beatpeople, etc)
If you liked Goblin Slayer or How to Build a Dungeon: Book of the Demon King, you'd like the other because they are both a bit dark and mature...
so just read 'em, k?
Tomokui Kanata has suffered an early death, but his adventures are far from over. He is reborn into a fantastical world of swords and magic-- as a lowly goblin! Not content to let this stop him, the now renamed “Rou” uses his new physical abilities and his old memories to plow ahead in a world where consuming other creatures allows him to acquire their strengths and powers.
1 vote
both take place in fantasy universes, with strong male mcs who build their own harems and expand their own communities that they rule over. Hajimekata is a lot more explicit, though.
The new demon king, Vermot the 13th, is bored of his life in the demon kingdom, so he decides to take over the human world. He heads there with his sword and his pretty maid, Sara. With his powers and abilities, he is easily able to take over the first kingdom he targets, reduce the surviving princess to his pet, and slaughter any righteous heroes that come his way. He loves how he can take whatever he wants with his own power in this new life, rather than it already having been given to him (as in the demon world). He's not planning to stop his conquest anytime soon...
1 vote
Both mcs are extremely powerful, and the manga centers around them building their harems. Both have explicit sex and rape, as well as blood and violence and a ruthless protagonist
In a world where demon lords build dungeons and devour human emotions, one rookie demon lord, Procel, has a new idea. Procel seeks to build a revolutionary new dungeon where humans and monsters can coexist. But first, Procel must defeat the Wind Demon Lord.
1 vote
These Manga Feature the protagonist building a dungeon his own way in another world as a dungeon master!
One sunny leisurely day, a woman visited my house and asked me if I were interested in managing a dungeon along with support from goddess. But of course, I refused. Eh? Shouldn't I ignore a person in trouble, moreover if it's a beautiful woman? No way! That's too bothersome, and why do I have to do that? I'm perfectly satisfied with my comfortable life now, throwing it away is just overly stupid...... ...sigh, fine, so it's go to another world, become a dungeon master, manage a dungeon and deal with the Mana circulation problem? Understood, but how to do it?
1 vote
These Manga Feature the protagonist building a dungeon his own way in another world as a dungeon master!
Ostracized and attacked by his home village after the death of his mother, the half-human half-demon Elliot establishes himself as a dungeon lord with the help of his father's succubus.
1 vote
These Manga Feature the protagonist building a dungeon his own way in another world as a dungeon master! Both feature dark themes and a sexy succubus heroine.
I’m a demon lord?! Blessed with unlimited freedom in this new world, it’s time to live the good life building the perfect dungeon! Reborn in another world as a demon lord, Yuki plans to use the incredibly handy online store that is the DP Catalog to create a super sinister dungeon where he can live the easy life! But the moment he starts his new life, he encounters the unimaginably strong Supreme Dragon. Just when he thinks the end is already nigh, things take a bizarre turn in his favor! The Supreme Dragon, who turns out to have a major sweet tooth, transforms into a lovely young girl hell-bent on freeloading off him. And she’s not his dungeon’s only new resident. Within days, he summons an adorable slime and rescues a sweet little vampire girl too! While taking care of his new family, Yuki experiments even more with the Catalog by learning how to create his own weapons. Their idyllic days don’t last long, though, as an unexpected menace appears...
1 vote
These Manga Feature the protagonist building a dungeon his own way in another world as a dungeon master!
The Magician named Yard was suddenly summoned in different world as a Hero. The sorcery in this world is behind compared to Yard who came from another world. The other summoned heroes are also unreliable. Furthermore, it is not possible to return to the former world... In such a hopeless situation, Yard chuckles to himself. Get ready, humans of this world. This world where witchcraft is behind. I have enormous toy in this box. allow me to play with it. The Villainous magician named Yard tramples down the other world with overwhelming Dark magic!
1 vote
If you liked this, you'd definitely like this!¬ Both feature dark lords and their conquest of the world! Along with their sexual conquests too!
God left a dungeon in the hands of a boy known as the Demon Lord. After receiving multiple blessings from God, let’s start my life as a Demon Lord! …Or that’s how it was suppose to be, but God messed up and created the worlds’ weakest Demon Lord ever. To continue living, I have to continue making dungeons.This story is about an idiotic protagonist, a lonely demons’ child, an Undine who lives in a bathtub, and a princess who fell in love with the Demon Lord, even though she was human. A story that all unfolded during a bath.