Call Me Tonight

"Genocyber" and "Call Me Tonight" feature a seemingly normal individual who is capable of transforming into a powerful monster via supernatural means. People become terrified upon witnessing the monster's terrifying appearance and its power, so many attempt to annihilate it with a variety of weaponry. 

It has the same atmosphere. Both envolve monsters and are somewhat sexual.  

These two anime have a similar concept with a human falling in love with someone who is not a human/monster. They both focus on the idea on having feelings for someone who is not human and how it affects each other. These two anime also have comedy and a decent amount of blood. I think fans of one will definitely appreciate the other. 

Both are classics '80 OVAs from the horror genre, both are technically slashers, I mean there's a certain someone/something following a group of people, most probably teenagers, yeah, probably slasher, well Warau Hyouteki can be also said to be psychological horror, but it makes up for it with the similar production values from that time. 

Both deal with the main character having a monster inside of them. 

Both OVAs are filled with violence and fun, a good soundtrack and treat plot as a secondary element. 

Both OVAs are filled with violence, blood and nudity. They also have non-hentai grotesque tentacled monsters. If you like one, you will enjoy the other.  

Both anime are short one episode OVAs with a simple and linear plot, and a same style of storytelling. Also, the under budget-ness and the similar style music the OSTs have give these two anime a similar atmosphere. 

Both are dirty and weird, and have man beasts. 

Both anime have giant, grotesque, tentacled monsters with lots of violence. Urotsukidoji: Legend of the Overfiend has better gore, is more serious and is more erotic. I say that Call Me Tonight is like a tamer version of Urotsukidoji: Legend of the Overfiend. If you like one, you should enjoy the other.