I found this trick when I was fooling around with the mobs in the Ghostlands. I haven't found much use for this yet but this is how you can attack a mob without them fighting back. (This only works with ranged attacks)
1. If a mob is chasing you and there is water near by run into the part of the water that's deep enough so your character starts swimming.
2. Usually, the mob won't go any farther and will stay at the edge of the water and wait there.
3. Ok, usually if you attack a mob when you're in the water in will just evade. But if you wait until the mob starts returning to where it was before and you hit it while its running back, sometimes the spell will be successful and the mob will not evade it when you cast it in the water. This causes the mob to get hit, but it will not run up and attack you. Instead, it will just pretend like nothing happened.
I guess this might be useful if you want to cast a curse or something on a mob before you attack it but, the mob won't take any damage from the curse until you start fighting it again I think. Also, you can only cast one spell with this. If you cast anymore spells it will just evade. Sorry if this is a repost.