Fan Translation:
A genius beyond compare.
A modern-day Prometheus.
A peerless Adonis.
A man who spread Zeus's lightning across the earth.
A good rival of the King of Inventors, Edison.
A person that boasts of splitting even the stars.
The above are just some of the self-proclaimed titles he has given himself after manifesting as a Servant,
But what remains after this are only the evaluations of the experts given after his death.
In truth, he was a genius.
Even though he is wrapped in a cloud of machines after becoming a Heroic Spirit, that genius nature is strongly prominent.
Since it's being left lying around there, it has to be said,
It shouldn't be touched carelessly---
Trivia
its a pun for Metal Gear Solid and Mortal Kombat character (Raiden) as well as the other name for the Japanese Deity - Raijin.