Perhaps with full party control you could select two party members and tell them to attack in formation (eg. flanking).
The two characters could have skills in The Path of Co-operation which lists eight skills that allow the two to fight together. You both require a spare skill point and the level requirements for the skill before either can purchase it, and they both purchase it simultaniously. The skills could be as simple as flanking and be more advanced like playing ping-pong with the enemy being the ball and your Mauls being the bats. You could have one hold the enemy and the other gets a 100% success hit on them (damage reduced by armour). Simultanious blades from either side could decapitate an enemy (5% chance of success per hit per level).
So, any other gorey ideas?