That reminds me, awesome news that WoL becomes an even better tank with enhancements, some vindication for using him over Cecil...kinda haha One day I'll get around to maxing Cecil out. At first I held off to level his LB but don't know that I care to at 5* level, should call it a day and just level and awaken him. I haven't been too motivated since I know WoL will get his 6* soon and I haven't struggled with him in.
CoD, a lvl 80 refia, tilith, dark fina, 500atk Noctis + friend noctis
Don't have a Cecil..only other tank I have is charlotte.
I do pretty well until he starts casting death on my team and then it's a struggle to keep people alive, even using comeback with Noctis. Using Omniveil(cod) or Rainbowveil (Tilith). Refia doing embolden or curaja. Tilith healing as needed as well and sometimes celestial to boost all stats. I try to keep up using Comeback from Noctis, but ends up being a losing battle in the end. I haven't tried stacking rainbowveil with any other bara's yet though.
That's not too different from my team composition. I use Noctis-WoL-CoD-Refia-ExDeath normally but as I stated in the last post, swapped Ex for Vaan this fight. My Refia has DC but you using Tilith should make up for missing that a bit and you're just losing out on a tank to bring her in and I'm not sure how useful WoL really was in that fight to be honest.
The move you think is death is actually a move called "Swallow" and it's triggered on the third round if you use magic that round. I'm guessing you use magic every round with Dark Fina so that'd be the cause but I believe he uses it on the fourth round regardless unless you hit his next health threshold. That's what I meant by bypassing some of his abilities by hitting his different thresholds in my last post. He will bombard you with AoEs when you hit the new threshold and put negative buffs on you but if you have your defense buffs up, no biggie and you can use comeback with CoD to take care of the status effects. So basically the lesson is to put up defensive buffs BEFORE hitting the next health threshold and then try to qucikly DPS him to the next threshold before he does that "Swallow" attack. You can buy yourself an extra round before he does it by not casting offensive magic on him on the third round as I mentioned before. Also, don't use Limit Bursts or Espers on him as this triggers "Magic Breath" or something along those lines. For prep work, make sure you have the -ara spells for fire and ice, those are the only two elements he uses. Craft them if you don't already have them and get them on someone that can use green magic. All the better if it's someone that isn't a healer. CoD can but it's nice if you have someone else that can do it so she can focus on Omniveil but if it has to be her, so be it.
So first round, cast the two -ara spells and omniveil. If Refia isn't casting an -ara spell you can have her use embolden. I don't have a Tilith but if she can equip the -ara spells, perfect, you already know what to do this round with her but if she can't and has a SPR buff ability or elemental protection ability, use that. If you manage to get both -ara spells on and omni-veil, go ahead and have both Noctis' Warp Break and Fina do whatever her strongest attack is. If those three knock him into his next threshold right off the bat which I believe is at 60%, great! You should be able to weather the storm of attacks he does with those buffs and now won't deal with swallow for that first threshold. If you can't get both -ara spells and omniveil up on the first round because one person has both -ara spells, go soft on the initial attack so you can make sure to have all buffs up before the threshold break. You can maybe use the ability Noctis has for hp and mp regen party wide and just have one attack along with Fina.
Second round, if you don't have all buffs up finish that up, heal, and attack hard with everyone else. If you do have all the buffs up then you can just heal and go all out with everyone else trying to get to his final threshold before he can use Swallow.
From here it's just a matter of making sure all your buffs are up at all times, keep everyone healed and other wise DPS the hell out of him until dead.