Sometime you may have trouble with Mage's such as they are going to get away unless you have a huge level advantage if they want to run from you in Allods Online. So you have trouble dealing damage when they do stay and fight it out. It usually goes to a standstill for they can also barely touch you. It's doubtful they'll do enough damage to kill you, and it's doubtful you'll do enough to kill them, unless they, or you have the level advantage.

The stone barriers cost quite a bit of mana and also have a 45s cooldown. You can use grouping to beat mages since they are very weak to summoners and healers. And you can use either incredibly powerful hits which do more dmg then the barrier absorbs (rare). Or alternatively, use really weak hits that are super fast to break barriers.But it depends on your Allods Gold, this may be an uphill battle. Warriors and paladins in particular are vulnerable in some regards to kiting and the mage will try to keep out of range.

You can run behind trees and objects to break line of sight if at a distance move around between range attacks. This will cancel a lot of spells and make it harder for them to target you. Start with multiple quick hits if you can to try and negate the barriers or reflections and then follow with a stun or knockdown effect to delay them restoring them. Run around the mage whilst fighting to again reduce the types of spells they can use.