In this work, he is known as the genius scientist who invented the technologies still in practical use today. Due to his great achievements, he is hailed as the only sorcerer in human history, and even Edison, who was his rival in historical fact, acknowledged his talent. However, Tesla himself hates his research being treated as magic and dislikes the word magic, stating clearly that what he uses is strictly science. He opposes the gods' plan to destroy humanity—the catalyst for Ragnarok—calling it the abandonment of creation. He has slightly wavy brown hair parted in the middle and is relatively handsome compared to other human researchers; if he stays quiet, he's quite a nice-looking guy. In fact, Gondul—a picky woman who, according to her partner Brunhilde, could stab someone with a smile—fell in love at first sight, saying she would offer her body to him. Conversely, after the Volundr, Gondul would electrocute the overly familiar Edison or the old man Galileo. As a side note, the historical Nikola Tesla was also a very handsome man who received constant advances from famous women, but he famously turned them down and spent his life devoted to a female white pigeon he met in a park. For better or worse, he is a man of intense curiosity. Even in the heat of battle, he calmly analyzes Beelzebub's attacks and abilities, smiling with joy upon being hit and even asking Beelzebub to lend him his divine weapon because he wants to investigate its principles. This bad habit has led other scientists to call him a research otaku. Furthermore, his naming sense is incredibly tacky. It's so bad that his fellow scientists either blush or fall silent, and even the announcer Heimdall mutters during the match about how terribly uncool it is. He also asserts that keeping information secret is nothing but harmful to science, declaring that humanity has progressed by generously sharing newly acquired wisdom. Therefore, when Beelzebub sees through the constraints required to activate his trump card, Tesla Warp, he is the ultimate teacher who goes as far as to disclose even more detailed activation conditions himself. This is because he believes it brings progress to science and humanity. Born in the village of Smiljan in the Austrian Empire (present-day western Croatia), he spent his childhood there. At the age of five, he frequently visited the workshop where his brother, Dane Tesla (seven years his senior), was making a windmill at the request of a village elder. Dane named his workshop the Gematria Zone, which Nikola disliked; the alternative he proposed was Hyper God House. Even then, he held a strong interest and belief in science, saying that new discoveries are born from failure and that humanity has progressed through failure, which encouraged Dane when he was worried about the windmill. However, on a stormy day, Dane went to check on the windmill and was struck by lightning, burned along with the structure. While everyone in the village mourned his death and looked down in sorrow, Nikola alone believed that his brother would live on within science. The villagers thought his words were just the touching kindness of a five-year-old child. Later, although Dane's windmill was built according to the blueprints, it didn't move at all due to some defect. From that day on, Nikola spent his days holed up in the Gematria Zone his brother left behind. Six years later, Nikola improved Dane's blueprints and asked the villagers for one more chance to rebuild the windmill. Then, the windmill began to move as if life had been breathed into it. He was only 11 years old. Since then, Nikola Tesla ventured out into the world and continued his research throughout his life, and even after ascending to heaven in death...

A 19th-20th century Serbian electrical engineer and genius scientist, Nikola Tesla. He is one of the great scholars who brought electricity to human civilization by unraveling the power of thunder and lightning, which had been told as legends of divine nature in many myths. He is a great man whose name remains in the Tesla coil and the unit of magnetic flux density, the Tesla. A peerless genius. A man of unparalleled beauty. A modern Prometheus. The rival of the King of Inventors, Edison. The man who manifested Zeus's thunderbolts on earth. He is the demon of magnificent and brilliant wisdom. His wish for the Holy Grail is to complete the Nikola Tesla World System. It is the arrival of a new world where the alternating current he researched and demystified travels through space itself. To achieve this, Nikola Tesla will spare no effort in cooperating with the restoration of human history. While it was customary for cultural figure Servants in the series, such as fairy tale writers and mathematicians, to be summoned in the Caster class, he was the first cultural figure to fall into the Archer class (later followed by a certain sparkling poet). He is an Archer of many exceptions, to the point of absurdity, as he does not fire anything with a physical substance. However, besides describing being struck by lightning as being hit or shot, the term 'a current running through' is used as a synonym to express a powerful instantaneous impression on the heart, and in some myths and legends, lightning is represented as a divine arrow or a projectile/thrown weapon. Thus, him wielding that lightning as a weapon and becoming an Archer might not be wrong in a sense. Also, while the series of cultural Casters exercise some form of magecraft even if it's not their primary profession—and even Babbage, a fellow scientist, does so in the form of a Reality Marble worn over his whole body—Tesla, whose source of power is the physical phenomenon of electricity despite looking like magecraft, might be seen as not fitting the Caster slot... Well, though things like 'Magic (Physical)' do exist in the world... However, since the Caster class has the Item Construction skill, which means inventors are also qualified, it wouldn't be strange for Tesla to have Caster aptitude as well. Beyond this, though it's at the level of an urban legend, since the ship used in the Philadelphia Experiment is a warship, he might also have aptitude for the Rider class. First person: I (polite/formal).