Best DPS is actually a combo of Weapons Of Light and a full clip of a 100 round machine gun, bullets making about 1000-1200 damage each, then you still have time for about 5-6 IB shots worth about 15000 each. Total damage of about 200.000. Have 5 people do that and you smoke him on one portal run as long as you get 20 seconds or more for the shield. Easy peasy :)