Kayneth El-Melloi Archibald is the Master of Lancer in the Fourth Holy Grail War. He is also known as Lord El-Melloi, as he is one of the Lords in the Clock Tower.
The Lords (Monarchs) are people with a lot of reputation and respect that work as the Department Heads of the twelve faculties. Kayneth is the Lord of the Department of Mineralogy.
This Department is quite interesting in the Nasuverse, as is the class were some of the important characters of this world attend to, such as Rin Tohsaka, Luviagelita Edelfelt, and Yvette L. Lehrman (Lord El-Melloi II).
Kayneth is a very wealthy and successful nobleman, a renowned magus from the Mage's Association, and a Euryphis (Anyone who knows what Euryphis is can tell me in the comments?) lecturer in the department of Spiritual Evocation. Kayneth demonstrated genius level talent during his time as a student. He was the youngest lecturer to grace the podium of the Department of Evocation in its history. He has an ancient magical lineage that goes back for over nine generations. He was born with immense talent and rarely, if ever, encountered any hurdles in life. Due to his great lineage, he had extensive connections. He was expected to form the greatest faction in the Clock Tower. Waver Velvet is one of his students, but Kayneth cares little for him, especially after reading Waver's radical thesis concerning increasing magical potential. Kayneth decided to tear up his student's manuscript after publicly humiliating him during a lecture. Waver, in retaliation, stole Kayneth's artifact and entered the Fourth Holy Grail War. Kayneth originally intended to summon Iskandar, but with his artifact, a piece of the torn mantle of Alexander, stolen by Waver, he instead summoned the Lancer-class Servant, Diarmuid Ua Duibhne.
(Nice copy-paste from the wiki, author. You rock!) (Ignore this lame author comments, exams are killing my self-esteem)
He is engaged to Sola-Ui Nuada-Re Sophia-Ri, the daughter of the head of the spiritual evocation division, through an arranged marriage. They apparently do not get along and Sola-Ui considers Kayneth a coward for not going and attacking the opposing Masters face to face. While he loves her, she does not appear to share the same sentiments.
Both of these characters, Sola-Ui and Kayneth, are important characters through the start and past half events of the Holy Grail War. They died after Diarmuid by Kiritsugu's companion hands.
The only reason he participates in the war was merely to increase his own prominence within the Mage's Association. Similar to Diarmuid, he has no specific wish if he win the Holy Grail War, so they technically fit very well together.
In the end, Kayneth was afraid of Diarmuid stealing his fiancé, so he didn't trust him as much. In Diarmuid's final battle, Kiritsugu force him to use a command spell to make Diarmuid kill himself.
With Drako's battle against Diarmuid, he had changed a lot of events mentioned above and much others which aren't mentioned. And the result of that was…
[You have successfully changed a person's fate!]
[1 Fate Point obtained]
[You have successfully changed a person's fate!]
[1 Fate Point obtained]
[You have successfully changed a person's fate!]
[1 Fate Point obtained]
3 Fate Points, one for each of these characters that was no longer going to participate in this Holy Grail War.
Regardless of whether Kayneth and Sola-Ui died after this, it didn't matter. Their deaths were no longer related to the Holy Grail War, at least not the way they originally should have been.
Therefore, Drako no longer cared about what they were going to do from now on. Although Kayneth's Hydrargyrum Volume was an interesting thing, it could do nothing against Drako.
While Drako was thinking about all this, he heard a thunder-like noise.
"So here you are. However, you're a little late," Drako muttered as he looked up to the sky.
A flying object made a straight line through the sky and headed straight for its location, scattering purple sparks of thunder in its path. The sound was undoubtedly created by that.
Irisviel was mute with astonishment as she said in shock.
"...A carriage...?"
From its appearance, it was an ancient carriage with two bows. It was not driven by war horses, but by handsome bulls with muscles waving like waves. Its hoofs plied the space, pushing the luxurious and splendid chariot.
No, the chariot was not merely floating in the air. Its wheels thundered noisily; it was not solid ground, but thunder in which the bulls stood.
Every time the bulls' hooves and the chariot 'stepped' on the empty sky, violet rays spread like nets, raising the air with deafening roars. The prana sprouting from the rays was probably what Diarmuid could release if he used every ounce of his strength.
The difference in level between one Servant and another was quite great.
Drako already knew that the stats of each Servant would not be so different. What really made the difference between one Servant and another was his Noble Phantasm.
The Noble Phantasms of Diarmuid were interesting, but they were far inferior to the Servant that was coming.
Rider.
The person who had arrived was none other than the King of the Conquerors, Iskandar or Alexander the Great, with his "weaker" Noble Phantasm, Gordius Wheel. Although he had nothing of weak, being a Noble Phantasm of Rank A+.
No Noble Phantasm Drako had surpassed Rank A, except Laevatein's sealed attack, Rank EX. That said, a lot about the power of this Noble Phantasm by Rider, not to mention that he had an even more powerful one.
Normally, when enveloped by such a huge aura of lightning and thunder, the Heroic Spirit is most likely some kind of god of thunder. And if he was a thunder god with a connection to the bulls, the first one that came to mind would be the greatest of the gods of Mount Olympus. Although this chariot itself cannot be called a Heroic Spirit, even attached to a Heroic Spirit, it was quite threatening.
This was because, in his life, Iskandar had proclaimed himself a son of Zeus. He even had a Divinity of Rank C because of this.
The chariot went around the skies a couple of times before stopping and settling on the earth. It was placed exactly between Drako and the girls, who were still processing everything that had happened in the previous battle (not even five minutes had passed since Diarmuid's death). The dazzling light ceased as the carriage landed, revealing the figure of a muscular man, standing dominantly in command of the carriage.
"A king has arrived!"
This casual roar was almost as powerful as the thunder in the air. His fierce gaze almost had the power to drive Drako back.
Drako was a King in his own right, a Great Dragon King to be more correct. His aura was not inferior to that of Iskandar, so he would not be intimidated by it.
"It seems that I am late... I did not want Lancer to die so soon," murmured the King of Conquistadors.
He turned his gaze to Drako, and then to Mordred and Artoria, and then continued to speak in a stern tone.
"My name is Iskandar, King of the Conquerors. I am a participant in this Holy Grail War and received the class of Rider."