What can a Runemaster do in group versus group battles?
In small group battles you can deal damage with DD spells. You can root enemy tanks, and debuff them as well. You can nearsight enemy casters, healers and archers. You should probably NOT use your AE spells. The reason for this is that non-keep RvR battles are a place where single-target and AE mesmerize spells can make all the difference. If one group gets all or part of the other group mesmerized, they will win. If you break an AE mez with your AE damage, you will likely lose the battle for your group.