DreamWorks Dragons Dawn of New Riders

There are 3 different weapons that need to be upgraded (An axe, a hammer, and a sword) you get the weapons from chests in each of the 3 areas. Each one will need to be upgraded twice. The first upgrade taking normal stone materials you pick up from the world. The second upgrade for each will require normal stone material as well as a special item that you get from the 3 side islands that have puzzles on them (the other three islands have battles and locked up air strike dragons). Upgrade each one twice with Gobber and you’ll have your achievement.