Mouryou no Nie

The heroines lost a fight and get raped by tentacles and demons. This one also include human gang rape.  

Many parallels here, similar stories/setup, they both originate from the same company/creator, and most importantly they both take tentacle rape to the next level with a high emphasis on impreg. Some mind break, with explicit content that never crosses the line into guro. But if you wanna see tentacles at their most extreme look no further, girls get stuffed to the brim and filled up with copious amounts of demonic semen! Mouryou has some eggs, with Shoku having a big focus on bugs. Lovely!