[list][*][b]Name:[/b] Gilgamesh
[*][b]Gender:[/b] Male
[*][hider=Appearance A][img]http://i.imgur.com/1e4nxNa.png[/img][/hider]
[*][hider=Appearance B][img]http://i.imgur.com/9x1KCQC.png[/img][/hider]
[*][b]Personality:[/b] The first word that anyone would think of to describe Gilgamesh is 'egotistic'. As far as he's concerned, the world and everything in it should still belong to him, and everyone else is inherently beneath him. This extends to morality, too: good and evil are irrelevant; right and wrong are concepts that apply to other people. Fortunately, without large negative influences on his already-alarming personality, his actions tend towards the self-indulgent rather than malevolent.
Perhaps the saving grace for anyone that annoys him is that, despite being the alarmingly powerful King of Heroes, Gilgamesh's consideration of them as unworthy extends to putting effort into defeating them. Even powerful, respectable heroic figures barely merit any attention on his part, so normal people get even less. It's possible, but unlikely, to push him into fighting back properly despite this... but generally that's of the 'it's too late' variety.
Despite all this, it would be a poor idea to underestimate him. As much as his colossal ego clouds Gilgamesh's judgement, he's far from an idiot--and far more knowledgeable and perceptive than you'd expect. On top of that, his self control--despite tending to openly display his emotions--is impeccable; he's never going to do something simply because his emotions got the better of him.
[*][b]Abilities:[/b] Gilgamesh's abilities, per se, aren't terribly intimidating for a mythological figure of his status. He's strong, fast, tough... all pretty standard things, even if a normal person doesn't really compare, though he's definitely more well-rounded than many heroes. Charisma that's more of a curse (and his problems with Ishtar would suggest it is) is one of his few defining abilities... though then there the useful ability to acquire money more or less entirely by accident and constantly be fabulously rich.
[*][b]Equipment:[/b] [s]All of it.[/s] Gilgamesh, as the oldest hero, has a treasury whose value is beyond compare. Almost every legendary item or trinket can be found within, along with a vast host of less notable magical items--such as his armour, or the sheer amount of magic-resistant jewellery he owns (plus the armour itself is effectively immune). He even has some of the best wine to ever exist in there, probably with the cornucopia.
So what does he do with all these treasures? Shoot them at people. He basically uses peerless artefacts as ammo for a mystical sword machinegun. It's understandable when you aren't as skilled with the weapons as their original wielders, but it's a bit of an underwhelming use. 
Two of the Noble Phantasms inside the Gate of Babylon are, however, significantly more noteworthy. The chain Enkidu is capable of lengthening almost infinitely... and passing through the treasury and thus creating a rather entangling mess. It's far more than a mere chain against divine targets, binding them far more strongly the closer the target is to a god. The other is Ea, Sword of Rupture. More of a drill than a sword, its power being only slightly used is a wave motion gun. At full power, it would destroy the world.
[*][b]Brief Backstory:[/b] The very same as the legendary figure from the Epic of Gilgamesh, that literary tale more or less sums up Gilgamesh's life--clearly a bit inaccurate on appearances, but it's more or less the same thing. What the Epic [I]doesn't[/I] cover is his gathering all of the world's treasures before his death and inevitable ascension to being a Heroic Spirit. Then he got summoned for the Holy Grail War, hung around after getting doused in all the world's evil, and ended up getting killed in the end.
[*][b]Universe of Origin:[/b] Nasuverse[/list]