Honestly, when they changed it to where mysticism relied on imbuing and focus I had to remove it from template. There are some useful spells, but to take up that much of a slot of skills is pointless.
Especially that they changed purge magic where it won't dismount people.
Basically spell plague and hail storm are great for group fights. Plus the cleansing winds really helps when trying to defend despise or even trying to raid it.
If you had a couple mystics spamming hailstorm and a couple more people spamming explo pots you can take a bridge very fast.