MHZ isn't that bad, just make sure you can clear the first wave of lvl30 mobs, take down the 420k hp lancer dragon, have arash kill himself, and then release the mlb purely lvl90 np5 hercules you borrowed from a friend that's been sitting in the backline, being very angry. Use some skills to keep him alive, and use MHZ's high hit rate to charge np, and then attack buff and attack buff, and proceed to watch the angriest man alive do monstrous damage.
If you're able to get past Tesla, I think the one with Scathach isn't too bad granted you have a strong saber in your friend's list, and so long as you're able to finish off the Rider mini-boss without losing too much in terms of HP. Just use your first aid and emergency evade skills when they need to be used and you should be fine. Sabers are needed for Scathach but since you're likely stacking sabers for the extra Altrium bonus it shouldn't be too bad if you have at least one of them sufficiently leveled and another from your friend slot.