Most of Sojiro's experiments had revolved around animals, even though he would prefer them over people, it was much easier to get them in large quantaties without things getting someone's attention. So, the black-haired surgeon would have started with a series of tests that involved mutating the animals with extra limbs, organs, and things of the like. It took time until he had perfected the different procedures, claiming them one by one until he became comfortable with more extreme ideas. Soon he began mixing the different DNA of creatures together so that he could try and create a strong, better animal down the line. Sojiro wasn't sure what he was expecting to get from this but his curiosity couldn't help but push him further down these roads. It wasn't until he was a few weeks into the experiment, some of the chimera creatures having survived, that he thought he could put it to good use in body modification. There was no denying there was a deadly array of lizards, insects, and such in the desert and so that was how he was going to get his subjects for this experiment. At some point in the passing time, Sojiro had encountered a Kaguya boy that had allowed him to put a tail onto his body. When this happened, it had given him an idea that he could create something for himself but a more extreme version. While the tool created for the Kaguya was useful, it could be considered like prototype of sorts.
The tail that Sojiro had in mind for himself, was a weapon that would hopefully be able to administer a poison to what it struck. It was hard to get combine the DNA from the different kingdoms, blending them into a creature that was a true monster. Sojiro had wanted the tail to be strong enough to be useful in combat, ideally with the ability to retract itself when it wasn't being used. The other thing he had to make sure was that whatever poison the tail could generate in confuction with his body wouldn't turn around and kill him in the process, which was really the most important part. The first creature that he created of this concoction of DNA would fall victim to the poison that it created, which was not the effects that he wanted for himself at all. It wasn't until he got to the fifth creature and combination of DNA that there was a strand that seemed to be suitable for transplant. It was easily to take the goo from the creature and turn it into something that he could inject into himself, the syringed filled with a deep red liquid. With no hestitation, the man would jab the needle into his lower back and inject the contents. There was a seering pain that caused him to scream, slamming the objects around his room to the side while he dealt with it. After it had finally ended, nearly an hour, there was a new appendage on the man's body. It took some getting used to but between this and his other body modifications, the male was sure that he was ready to start the next step of his plan. He would need to take some time to recover and heal up, but once that was done, he would need to start planning.