Conjuration.
All conjuration weapons will look the same and glow. The only thing we should be able to do is change the glow color of the conjuration weapon. This way nobody has to worry about styles. There is only one uniform style for the conjuration weapon.
Maybe we start with the usual known weapons for the first release. Change the flavor of the skills of the known weapons.
Then just like mythics, other sets, etc. New conjuration weapon arts can be added in newer chapters.
So now that we have that solution out of the way, tell us why we can't have a new weapon type in the game.