Dark Fantasy Recs

Hello looking for series that are dark fantasy. With human experiments, revenge, betrayal, no harem/romance (unless it not much of the plot)

Series I have read/reading and liked:

- The Executed Sage Who Was Reincarnated as a Lich Started an All-Out War

- The Death Mage

- Nito no Taidana Isekai Shoukougun: Saijaku Shoku "Healer" nano ni Saikyou wa Cheat desu ka?

- Nigoru Hitomi de Nani wo Negau: Highserk Senki

- Fukushuu wo Koinegau Saikyou Yuusha wa, Yami no Chikara de Senmetsu Musou suru

- Boku no Nakama wa Isekai Saikyou Undead

- Overlord