Okay, spent some gems and bought a key.  Saw exactly what happened.  Switched to Wix as defense lead, but the reason Malkith #1 is dying is he doesn't have as many buffs and doesn't get shields grown as fast.  The DL focuses all damage on this one, and keeps the shields from getting high enough to outpace the incoming damage.  Thus, his shield eventually breaks.  Malkith #2 then gets beat down since DL is pounding all shields.  Then, Ninja got picked off.  Laz was reviving, so were Malkiths when they came back in, but without shields forget about it.

Then, there wasn't enough shield extension for Wix and Laz to keep up and they all died.  Took about 32 DL turns.  So the real question is how to get Wix to outpace DL ramp up in damage.

It took me 3 months of trial, error and a lot of help from the forum to build a speed tune team for UNM.  Check the CCs and see if they of them have a speed team for the champs you have.  

Good luck.  

You've already more-or-less answered your question. This team relies upon the shield growth outpacing the damage. If at any point that fails to hold true, the team dies. The longer this takes to happen, the more damage you end up doing.

Here's the thing - the VAST majority of your damage output is simply based around survival. You literally do not need any damage *at all*. Just warmaster/giantslayer alone, spread across the 1500 turns, is more than enough to get you well above 100M UNM dmg per key.

So - Wix and Malkith x2 do your buff extends. Great. The next part of the equation is the actual buff count. The team you have does not end up having a full complement of 10 buffs, so if you drop one of the other two and simply add someone who places Continuous Heal, you'll get to 10 no problem, since they'll stack and then be extended indefinitely.

That in and of itself is probably sufficient. So, drop Ninja, and add anyone who can place CH.

Is Black Knight on 3 turn cooldown good enough to do that?  I have him.  I also have Fyna, and in shield gear, she starts team with 4 buffs, Wix 2, and BK would make 7 unique buffs to start first round.

Both Fyna and Wix add more, targeted, and BK would add cont heal.

I still may need to get Wix higher on acc to land his atk down, too, to lessen damage.

Thanks for further thoughts!

The cooldown is irrelevant, really. The buffs get extended infinitely.

I'd just pick an epic champ that brings CH, really. No point in wasting books on a lego champ just for this.