What I did was summon an NPC and had them be a distraction until I made it to the fog gate before sending them home. Then, I quickly buff my sword and run in. You just got to try and pull off as much damage off as you can on the first one before the 2nd one shows up. If you can't kill Lud before Zallen joins in, then just take it slowly and hit Lud when you can. When it gets down to a 1v1, it gets easier, but beware, when it gets down to 1v1 and the boss is at 50% health, they will do a health regen buff, making it pointless to attack them. Just dodge around until the buff wears off and it should be an easy kill.