The monster you guys created.

Chapter 15.5 : GYATTTTTTTTTTTTTTT !!! (Lemon)

Rimuru : Are you sure this is safe ?

Izumi : Absolutely.

The girls in Izuku's Harem is currently talking in secret about something suspicious. 

Gudako : But what if it doesn't work ? He is the Omnipotent Mortal after all.

Izumi : That is the case. He still limit himself as a Mortal so he can still get affected by this thing. He may be immune to Death, Nothingness and yada yada more stuff but he never interact with this special thing right ?

Izumi then put a potion on the table which said. "GYAT potion".

Keiko : Well, i have no offend to this idea.

Chiyoko : Me two.

Akeno : Me three.

Rias : Hah, i guess no point in decline it now.

Yuuki : Yup.

All the girl then raise their hands up in the air and agree with Izumi's idea. (Amira, Yukiko and Satsuki are not in the harem yet.)

Izumi : Alright, let do this.

The girls : OK !!

Later that night, as Izuku is sleeping. Izumi sneak in and drop the whole bottle into his mouth.

Fem Rimuru : Wait, didn't you say only a few drops ?

Izumi : Oopsie~.

Rimuru : Gosh, i already have a bad feeling about this.

They then return to their room.

Izumi : Alright, Rimuru-chan please drop something and bow down to take it.

Rimuru : Ok. "I'm immune to physical damage so i guess it is fine."

Rimuru then drop a empty can on the floor and bend down to grab it... As soon as she did it.

??? : Did you pray today ?

Rimuru : Eh ?

Izuku appear from behind and start to... Backshot her.

Rimuru : OH AH FUCK AHH GOSH AHHHHHHHH~!!!

Izumi : Oh my~.

Rias and Yuuki : Ah~.

Akeno and Keiko : Ara ara~.

Gudako and Chiyoko : Woah~.

Rimuru : W-wait Izuku slow d-down a bit OHHHHHHHHHHHH~!!!

Izuku thurst even harder inside and Rimuru can't do anything but moan as hard as she can.

Rimuru : OH SHIT FUCK GOSH OH AH OINK~!!!!

Izuku then continue to Smash her puss and ass for 8 hours before disappear. Rimuru just lay on the floor as cum leaking out of her pussy.