The Weapon Master is wise and strong, but he acts negatively when you say "no" to his question about going to the Quicksilver Vault and the Arkeyan Armory. He has great knowledge over the ancient Arkeyan civilization.
Skylanders: Spyro's Adventure
The Arkeyan Weapon Master had laid dormant on an isolated island in the waters of the Ruins for 10,000 years and was presumed to be a statue by the inhabitants. After the Eternal Fire Source was restored, the ancient statue awakened to help the Skylanders retrieve the last components to rebuild the Core of Light: the Quicksilver and Eternal Magic Source, from Quicksilver Vault and Arkeyan Armory respectively.
The Wii version has a glitch with the Weapon Master that happens when you say no to going to Arkeyan Armory after finishing Quicksilver Vault. This causes him to revert back and stay in his sleeping state. If you run into this glitch, you will have to reset your game.
Ironically, he thought he found the wrong person to help, and to go back to sleep for another 10,000 years.
Ironically, he resembles Alphonse Elric from Fullmetal Alchemist.
It is possible that the name Weapon Master refers to that subspecies of Arkeyans. If this is the case, the various projections called Weapon Master around Skylands may be different individuals. This is further evidenced by the fact that in Time of the Giants, at one point, a pattern with the Weapon Master's shape in the center can be seen on top of one the Arkeyan buildings.