A knowledgeable fan of Neo Angelique has tried to fix this page to give an example of how a character should be described on this wiki. This article wasn't detailled enough and if you don't know a character's age, you don't know enough to teach someone else about them.
I added more information, but it still isn't perfect. I would have added his story role, but I don't want to give spoilers. And it may confuse people who only know Abyss.
To know Yorgo well, it is esential to read books based upon the game, and take notes as you do so. The game gives most of what you need to know, then the game guides, light novels and two mangas plug the gaps. Some characters have birthdays, but Yorgo is too busy to have one. Abyss contains barely anything about Yorgo, except that he 'gave Ereinfreid a home' which is hinted at in one of the mangas anyway.
Also, I made it focus on the game while linking in the other iterations of Yorgo too. The game is the main iteration from which all other iterations spawned so it should focus on the game.
The 'debut' bit is nonesense because most characters appear in the first iteration of the game, very few join at other points and the ones that do tend to be exclusive characters to that iteration. Some, however, are route-linked in the game.
The version of Yorgo in Abyss appears to be a different character entirely and much less is shown. Abyss is not an appropiate media to judge the characters upon.
He is also the older brother of Rayne. They do not appear to get along well, as they have many differences in views. However, they do have some degree of respect for each other.
Garnet is seen describing Rayne as one of Yorgo's younger brothers in volume two of the manga by Mika Kajiyama, meaning he may have more than one younger brother.
In Abyss, he appears to be an entirely different character. Both his physical appearance and personality drastically change. The game version is a truer Yorgo, as he is much more developed as a character and consistent too. The manga by Mika Kajiyama and Carnival Comics from Koei Game Comics Collection, as well as all editions of the game, Light Novels, game guides and Memorial Book go with this version of Yorgo. It is only Abyss that doesn't.
Yorgo usually gives Angelique the electrocution chair (AKA trying to extract her power) so when he calls Ereinfreid an 'idiot', this makes no sense. Yorgo wants to use Angelique as a battery to power up the Jinx.
He doesn't appear often in most storylines, but can be lured out of his cave by heading for a route deeply linked with his younger brother.
His name can't be written in Kanji because it is meant to be written in Katakana! Yorgo is not a name originating as a Japanese name. It was taken from another language so it's only correct to use Katakana to spell it. Edit
Yorgo has deep muted red (almost maroon) hair, which is slicked back with a few strands at the front. His skin is rather tanned. His eyes are shaped like his younger brother's but are much smaller, with his signature indents around them.
He is frequently seen wearing a foundation uniform. However, he will occasionally wear a few other outfits.
He physically resembles Oscar from Angelique in some ways. But this is more-so for his game sprite.
Yorgo is very serious and is rarely seen smiling. He is dedicated to the foundation and tries hard not to let personal matters get in the way.
He is rather vain, as is shown when he smiles (for the first time in forever) at his own reflection in a mirror. This happens in the Carnival Comic from Koei Game Comics.