Hey, it's that guy!
He still talks a lot!
He still carries Genji Equipment!
You can fight if you want, but mostly you're just waiting for Gilgamesh to realize who he's up against.
Gilgamesh: Zounds! 'Tis no beast, just Bartz! You should've said so from the start! Oohhh, I don't like it here... Creepy monsters lurk around every corner, and I can' find the way out... Cripes... *sniffle* ...I'm gonna break down! Anyway. How did you get here? Or rather, how does one exit?
Bartz: Oh, just go that way, then...
Gilgamesh: I see! Let us egress posthaste! Say... afterwards, what say we have a few spectacular adventures, just us five?
Bartz: ...Um.
Gilgamesh: ...Oh yes, that whole savng the world thing.... phooey. If you make it out safely... Hah! No ifs about it. I'm certain we'll meet again. At that time, I hope you'll consider me a... Uhh...er. *cough* Never mind, ha ha! Hasta la bye-bye!
And now Gilgamesh wanders off, gets lost, and stumbles into almost every other Final Fantasy game before finding his final reward.
He shows up next in Final Fantasy 8, when Odin is defeated and his Zantetsuken flies into the sky from the battle. The Zantetsuken splits the sky open, and Gilgamesh catches the blade.
Gilgamesh shows up again in Final Fantasy 9, having eschewed weapons collection for card collection. He's back in 12, showing up with a full complement of faked series weapons for a few battles starting on, yes, a big bridge. I'm told in 13 he's available as a downloadable sidequest or something, where he starts the battle carrying various guns before throwing them aside, drawing his usual array of swords, and starting the battle for real.
And as we've seen, he's been retconned into Final Fantasy 1 in one of the optional dungeons. He's also available for a fight in the sequel to Final Fantasy 4, and retconned in as an esper in Final Fantasy 6.
He even shows up in the Dissidia sequel, but outside the normal summoning of interdimensional heroes and villains fighting for the sides of good and evil. He just stumbles into the middle of the conflict, wondering why everyone
else can't remember who he is (on account of the memory-wipe that's part of the series backstory).
In Dissidia, Gilgamesh is something of a semi-lethal joke character. Every attack he does is with a random weapon: Excalibur, Excalipoor, Zantetsuken, Genji Blade, Masamune, Battle Axe, Naginata, or Chicken Knife, and each weapon has varying reach and attack power. Excalipoor only does 1 damage on a hit, for example, while Excalibur does double, the Battle Axe does random damage, the Masamune crits more often, and the Chicken Knife does more damage as Gilgamesh's Brave is depleted.
Gilgamesh's EX Mode is his Gilgamesh Morphing Time, has him turn into his monstrous form to wield eight random weapons at once to somewhat normalize the effects of his random choices -- but it's still possible to do an attack and end up smacking the target with eight Excalipoors.
In his EX Burst, Gilgamesh searches for the Strongest Sword:
Dissidia 012 [Duodecim]: Final Fantasy - Gilgamesh's EX Burst: Strongest Sword (English)And given his vaguely Deadpool-like habit of noticing that he's in a game, as a villain, fighting to steal weapons from the heroes, he starts his EX Burst by rushing at the camera and busting a Gilgamesh-shaped hole in reality. He starts his EX Burst by
breaking the fourth wall. After that, it's just a matter of nabbing the right sword as it happens to fly by. If he's successful, he finishes off the EX Burst with Ultimate Illusion, which as far as I can tell isn't based on any attack he gets in any game he appears in... but an "Ultimate Illusion" is the last of a series of things that is impossible or improbable. In other words, a "Final Fantasy".
If Gilgamesh grabs the wrong sword...
Dissidia 012 [Duodecim]: Final Fantasy - Gilgamesh's "Failed" EX Burst: Excalipoor (English)He ends up with Excalipoor, of course, so that each hit does only a single point of damage. As shown in the video, it's possible to cherry-tap your way to victory by
intentionally choosing Excalipoor when your opponent has fewer than 5 Brave left so that it finishes them off anyway...
If Exdeath and Gilgamesh fight a battle in Dissidia, the text for Exdeath's EX Burst changes. Instead of "The laws of the universe mean nothing!" the initial box reads "You worthless fool!", and instead of "Neo Almagest" the textbox reads "Fall to the depths of the Rift!" Exdeath is the one who banished Gilgamesh to wander between dimensions in the first place, so the two get a callback to when that initially happened.