Senket you seem to have the feint legacy, wield a no remove weapon and toss on a shield and spam feint while the mummy whips out scourge and vamp. You use the shield to minimalize the number of ripostes and if you keep feinting you open up rounds for the zombies where he won't have flourintine/riposte going for him and make him really consider using that 4 round flurry move. also it gives you plenty of time to throw out a few maledicts if he switches targets away from you without lagging you up much.

If anything have one of you focus on absorbing the melee and the other focus on either maledictions or pure damage both of you trying to maledict didn't seem to do it as neither of you was able to stay in the fight for long stretches.