Mayuri was a scientist as heart— he wanted to do tests, experiment and solve scientific mysteries, so it was only natural that he wasn't pleased whenever he had to go to the living world to kill hollows.

He couldn't understand why they didn't just send somebody else, however he ended up stumbling upon a very interesting specimen.

It was a 171cm, 42kg, female, human corpse, which seemed to possess human intelligence, despite its state. It seemed to be in the nineth day of decomposition.

Now that was truly intriguing for Mayuri, so of course he attempted sedating and bringing it back to his lab, however sedatives didn't work, due to it already being a decaying, dead being, which did make sense, even if it complicated everything. Much to his luck, it wasn't hostile and lacked any meaningful strength, so restrainting it worked like a charm.

Now, Mayuri was in his lab, ordering around his underlinings to start preparing supplies to start testing the creature, which was currently in a special room with -10°C temperature and no oxygen, to slow the rotting. He didn't want it to become just a skeleton before he could figure everything out.