This is definitely far off from now, and while playing I couldn't help but think of what comes next after Legion and our artifacts.
The only route I could think of is that we would be able to create our own artifacts with expanded aesthetic customization. They could also be given personal names, and extra customization could be unlocked.
How extensive the customization could be is another thing. If one has a sword, then I imagine they could change the hilt/blade/guard/etc. along with unique particle flairs.
I'd also imagine that they'd be less class focused, and one just chooses what weapon type/s they want to build while the appropriate stats/traits are allocated.
Thoughts?