Kujiraoka explained some of the gameplay concepts for the character. Similar to Butz, Gilgamesh brings out a weapon with each attack, then puts it back after the attack. However, the weapon Gilgamesh uses is random. He selects one of eight vastly different weapons with each attack.
With this random system in place, it may seem like the character would be tough to use, but Kujiraoka assured that this isn't the case. He also assured that they're making adjustments to the character so he won't just be a joke character.
Asked for some weapon examples, Kujiraoka mentioned Excalibur and the impostor weapon Excalipoor. Excaluibur will make Gilgamesh's attacks double strength. Excalipoor, as one might expect, deals just 1 damage.