It's not efficient for points at all (1.37-1.5m) but I don't have problems with Max, Mariudeth, Zelnite, Darvanshel, Elza, Max.
Bring Marauder set and save at least 3 of the fujins for the round after Mare - it only takes 3 BB's to kill her.
Loch is usually near dead after the first round of SBBs with an attack potion. God Pierce won't go through Darvanshel's SBB - only Mariudeth is a risk if he gets hit by a regular attack first. Then, you can use potions to cure and normal attack kill him in the turn or two following that.
For Mare, if she doesn't die from Mariudeth, Elza, and a Maxwell, guard on the second turn then finish her on the third.
Mariu, Max, Zelnite, and Darv are dual sphered, and most of my units are wearing Amanos, Geldnite, Heavenly, etc, while Darvanshel has the usual Evil/Dandelga. That might make a difference.
You can definitely sub out some of these units e.g. Duel-GX for Mariudeth, or make Zelnite leader if you don't have Maxwell, with Kuhla or Ulkina in place of Elza or Maxwell respectively (this is a very poor sub but I've seen it done with ease). Narza works in place of Darvanshel too, but with these changes the fight slows down dramatically.