Fate series, which was originally an adult game that gained its popularity mostly with the successful erotic-content-free adaption.
A brief introduction according to its Universe-
The heroic spirits (英霊 / lit. Legendary souls) are usually based on Folktales / Legends (Arthur, Jeanne d'Arc),
or historical beings that did affect to human society (... forget about some random chars, everything has exceptions).
Which later became available for summoning and served as “servant”.
As I know, the popular characters are mostly the ones from "Genesis 1 ", such as Gilgamesh, Lancer, Saber"s", Archer and so.
The character pool got boomed up after the introduction of the spin-off mobile game Fate/Grand Order.
Now, I want the name of one of them, which is distinguishable by the appearance.
You can find the answer through the list Here
Format - copy/paste as you like.
hint - colors appeared in the preview icon: red, gold(or yellow, whatever).
side hint - Wat
An optional trivia introduction might help for searching the character Worth to read