Now in Erebus, you can see the stone, wood and ore. If you use tools, you can get these materials.
Stone: Felling axe
Wood: Timber cutter
Ore: Digging shovel
Collect these materials and Class equip scroll (drop from class coliseum) , you can get class equipment from transmutation.
Timber cutter, Felling axe and Digging shovel will also drop from the chests in Erebus. And if you use the advanced key, you will have more chance to get them.