Infinite Treasury in the multiverse.

It has been 2 days since I arrived in Nazarick, and my relationship with the denizens have been improving, slowly, and by slowly, I mean molasses in a canadian winter. I mean, I think they don't want to kill me in my sleep, but that might only be to Ainz's order though. On a side note, I have begun sword training with Cocytus, the beetle looking one. I asked him for sword lessons, and the look, if it could be called a look, was one of confusion. 

"Why would you want to learn from me?" he asked. It was a strange request, and I knew this but I figured getting training from the best swordsman in Nazarick, I think, it would be a wasteful opportunity if I didn't. Plus, Harry spoke really highly of him at our call yesterday and he seemed to have a favorable opinion from Cocytus himself. 

"I wanted to learn swordsman ship from such a warrior" I said to him, my words being honest. He cocked his head to the side for a little bit, his mandables clicking before he agreed, and I can tell I gained some approval from him. "All right, but we start now so get a practice sword, and I wont hold back" he said as I summoned a sword from the vault through suspiciously familiar golden portals. The sword was made of reinforced bamboo wood, magically of course, and could withstand any attack. 

Cocytus himself had a wooden katana himself. "Prepare yourself!" he said as he dashed forward which seemed as if it occurred in the span of me blinking. I ducked and was promptly smacked in the side. "Keep your eyes and ears on all sides of you!" he roared and begun again. I slashed at him which he dodged quickly but I was hit everytime. "Remember, if you see an opening, a slipping chance, take it!" he bellowed, and I realize he could not teach well. 

As the training was gradually going on, I was gradually adapting to his attacks and was able to land a few hits, still less than his by a mile, but still hits none the less. I was growing a bit unnaturally, was it the vault or the actual battle between someone who could potentially be life ending, maybe. I have had a lot of maybe thoughts, but I couldn't accurately gauge my own strength in other worlds. 

We have been training for a couple hours, and my body was drenched in a lot of sweat, and halfway we decided magic enhancements were a good idea, so my mana pool is a bit low. As I exited the ampitheater, I teleported to Ainz's office with a guild ring, which I was given by Ainz in exchange for some other magic items. 

"Hey Ainz" I said to him as he was working on some paperwork while Narberal Gamma was behind him with Sebas Tian. "Hey John, what did you need?" Ainz asked me. I wanted to experiment with some of the items I gave you, specifically the ouraborus and Seeds of the World Tree" I told to him as he raised his non-existent eyebrows. 

"Don't worry, I have endless amounts" I told him as his eyebrows rose further, but agreed and we both teleported to the Amphitheater. In his hands was a ring and some seed shaped items. These were the world items Ouroboros and the World Tree Seeds. 

The Ouroboros allowed the user to make a wish to the game devs for something that they had to approve, while the seeds allowed a race change. What I wanted to do was expirament with the wishing and race function so I can gain the positive traits of a race while remaining functionally human. 

As I relayed the plans to Ainz, he still seemed hesitant on using them, but I was able to assuage him. "Alright, what race should I pick?" I asked Ainz as he was the only one here right now that could tell me about certain races. 

"Well, you could become an undead like me, specifically an overlord" said Ainz. It sounded like a good option, considering the racial advantages like not requiring substance, mind control immunity, etc. But I also wanted him to explain some of the others to me. He went on a tangent about what he knew, but he seemed adamite on his choice of the undead. 

"Alright, lets give it a try" I said and we activated the devices and I could feel a stream of information enter my brain as I uttered my wish. "I wish to gain the positive traits of the undead while still being human!" I declared and I felt the Ouroboros works its magic as I felt my body undergo a change, one that could be seen by the now curious Nazarick floor guardians. 

The items then disappeared as I landed back down on earth. As I opened my eyes, my body seemingly changed, and I felt as if my very instincts and preconceptions were overwritten, as expected of a world item classified as one of the twenty. 

My existence was improved, for a lack of a better word. I no longer needed to breath, I was immune to mind control, sleep immunity, etc. It was weird yet it did not feel uncomfortable to be this way, as if it was meant for my body. 

"How do you feel?" asked Ainz, hoping the expirament was a success. I grinned at him and said "I feel great". He grinned, well he tried to grin, and we all celebrated in the experiment. The floor guardians seemed confused so we explained the expirament to them. I grinned at Ainz as I came up with an idea. So, we tried to use Ouroboros to lessen the racial penalties for Ainz, and it worked. 

He was now resistant towards his inefficiencies, and I had a feeling his future opponents were not gonna like how his racial weaknesses were not to be taken advantage of. Long live Ainz the damage sponge!

A/N: I plan to end the arc in the next act so I can progress the storyline into a further direction. Also, how did you like what I did with the world items, was it good? Anyhow, hope you guys enjoyed.