I tried removing the black outline again, I was able to without any problem, but they do not look like master of magic units anymore. In master of magic, that black outline was noticeable and taking it away changes the units appearance a bit more than I expected. I will post a screenshot for comparison.
In this screenshot, we see some Dark Elves casting their magic blasts at a Klackon force who are about to pwnzer them. (The blue swirlies are the magic blasts mid flight)
