Heros have levels, Artifacts have levels, Sparring pit, Gem Mine, Great Hall and Market all have levels of one type or another.  Why not the Forge? One possibility would be a graduated system to decrease the possibility failure when applying glyphs to artifacts. Another would be a tweaking of the re-working of artifacts with the various ores to enable a choice of which sub-stats would be included on the re-worked artifact/accessory. It could be used as a possible revenue stream using silver and/or gems, or a new resource (gold? platinum?).  just a thought...