[Suggestion] Specialisations

I don't know whether someone has suggested this, or not, and I know that it would change the basic idea of PoE but here goes. (Also it could already be a thing)

Specialisations
When you reach max level, very rare drop that unlocks a new Specialisation, not weapon Specialisation but complete Specialisation (including Weapon Sets). Therefore you can change Specialisations on the fly (or maybe in a Hub Location).