Visual bugs all the time.

[Azarael]

I had this problem on a laptop with a dedicated graphics card as well as integrated graphics. If the integrated graphics were being used in full screen, spell fx had issues.

If you play the game with integrated graphics, you will get visual glitches, especially on transparency effects. There is no solution other than to use an actual graphics solution.

[Dathros]

bump, hopefully OP is still active - also everyone else who experienced this bug:

I had the same problem, all my spell effects would just be weird black stuff. This is what fixed it for me:
I went from fullscreen 1600x900 to Windowed display 1600x900.

This is definitely what caused it on my end because as soon as i switch back to fullscreen with whatever video settings im back to having weird spell effect bugs!

MY HERO!

Back to the game btw, sorry for the "late" reply :3