Looking at his skill list, Rezar scrunched up his eyebrows, he had almost forgotten that he had been given 5 platinum elys when he went ahead and announced himself king back in Goblinshire. Never the less the skill combining gems were a resource like his skill points, and he was about to use them., he was told that you couldn't have more than 15 passives and active skills at any given time, to get a new skill you either had to delete an old one, or combine two skills into one stronger skill to make space for future skills.
Rezar understood that as another way Elysium tried to keep things in balance, with too many skills, it would be almost impossible for some people to be defeated, and even then with stronger more focused skills, it made people more focused as opposed to being a jack of all trades and a master of none. So while the amount of classes you can get is endless, the amount of skills you can learn in a particular lifetime was very limited.