Making levelling easier and giving ossuary another purpose

Levelling one class to 20 can be a big task and having to level the others to 20 or 10 just to try them out is too demanding and even most veterans will never have levelled all classes to 20 in a single season. Other games like mistfall solves this problem by giving you an option to buy max level on any class for cheap if you have one class at max level.

The ossuary should give an exp bonus, perhaps 100%/300%/1000% to all your classes below the level of your highest. This way ossuary has a cooler purpose that you can directly feel in function and more of an identity.