This is a successful run of the optional boss Termina after the free January patch which raises the level cap from level 50 to 100.
This also increases the level cap of Termina and Pamira, meaning they hit like trucks and well, they'll attempt to wreck your day with one shots if you let them.
The team is already level 100, but this is due to the fact that every kill you land on either of the optional bosses nets you an absurd amount of exp and cole (200k worth!) and essentially, if you started at level 50 with a level 100 Termina and Pamira before the patch kicked in, expect 8+ levels per successful takedown.
There are two setups, and I demonstrate the second one (which works better at level 80+).
Team layout is (Front/Back) Sophie/Lydie , Mattias/Alt and Suelle/Firis.
It's mostly self explanatory - Sophie charges her combination bar like mad, because she simply doesn't care - She has 2 automatic revives, a guts activation, and a failsafe resurrect (once) from Lydie.
If she DOES survive, she gets some HP back after the hit. If she survives and the elixir triggers, she gets a token amount of HP, a second heal of about 50% of her HP, and +attack +speed up.
Each support action Lydie makes charges the combination attack.
If Sophie uses the candle, and the time card activates, Lydie gets to react, further charging up the bar. Most importantly, Sophie is allowed to activate her combination attack when it is NOT her turn.
Under normal circumstances, no one else is able to do this (Firis can in theory, if you somehow got Firis to throw a Thunder Stile then switch over to Suelle before the second card activates because her flow attacks have 1 shot) which basically means that Sophie does not care whose turn it's supposed to be, and she can be surprisingly offensive when she heals.
Mattias and Alt are there just to load damage when they can. Weirdly, even though Mattias has more HP and defense, Sophie is a more reliable tank.
Suelle is there to front load damage, as well as sustain damage since Firis finally gets a flow attack that can react to Suelle's skills at level 80. (Firis/Suelle's combination attack is not very useful, but given the candles, the Sophie/Firis combination attack is even worse.)
The rest can be figured out. Sophie is surprisingly useful, and holds the entire team together dealing respectable sustain damage, healing everyone and debuffing Termina, while Mattias and Alt beat her down with skills, and Firis and Suelle keep dishing out sustained damage.
There are probably various tweaks to be made (redoing the wind and the frost bomb for extra damage might be worth it, and maybe trying to tank the elixir an extra 5 quality might be worth it) but all in all, it's a setup worth considering.