I'm gonna share my personal experience doing a lot of TC during the campaign, trying to use different setups as well.
Gonna use Spoiler because it's gonna be a long wall of text.
The setup I find to be most efficient is the following
1x RUN
1x SAM
1x ddCOR
1x WHM
1x BRD
1x GEO
(1x RDM)
RDM not necessary, but if you bring one he's gonna be in his own pt.
Dia3 can give a small boost to kill speed on Wave2, Wave3 and TC. Haste2 allows you to use a song slot for a different buff (another Minu or Herc Etude)
These pros might be completely irrelevant (depending on your pt's dps) because by bringing a RDM you have a 7th member and hence more HP for the TC itself.
Another QoL thing is that a RDM going /BLM can Silence 100% with Elemental Seal+Saboteur, for a longer duration and without having to rely on Immunobreaks like GEO or WHM.
RUN can be /SAM if he wants to help with DPS but I think it's irrelevant.
Yagrush kinda needed for the WHM.
/WHM for the BRD, gonna help on Wave3 if fulmination goes off and gets the WHM. If the BRD stands out of range he can paralyna the WHM very fast so that he can use yagrush to paralyna everyone else.
I'll skip strat for first 3 waves, it's easy.
As soon as Wave4 start (TC himself) the BRD will NiTro Horde Lullaby everything then: Clarion call > apply a 5th song, > Soul Voice > Overwrite all songs with SV ones.
While NiTro is still up, apply a SV Wind Threnody 2 on the Tumult Curator itself. This part is not necessary if you have a RDM, but relying on the GEO and WHM to land silence, it helps a lot. Can also land Nocturne/Elegy if you want and/or don't have a RDM.
GEO will get ready to use Indi-Fend, Geo-Fury, entrust Indi-Attunement on the RUN. Bolster gonna be needed.
Meanwhile all this process TC will be slept and the RUN can Flash/Foil to generate enmity.
COR rolls will be the same Crooked SAM + Chaos used throughout all the fight.
Once everyone is ready wake up the TC with a Dia and zerg it fast. RUN will Odyllic Subterfuge (helps if the TC uses the AoE Stunga move) then One For All then Valiance (with merits you still get MDB), rune types don't really matter that much but I'd say make sure there's at least one for the element of the day.
WHM will Sacrosanctity and after a while Asylum (Gives Meva with JPs)
SAM will of course Warding Circle at pull and then Hamanoha right on engage.
So basically in this fight you can't survive more than 2 Astral Flows. Maybe a third if you're lucky, but basically you need to kill it fast. Most our attempts we killed after 1 Astral Flow, sometimes right as the first was about to go off.
One very small thing to consider if you're struggling with the kill speed (and hence getting a third astral flow)
1) The WHM can Accession+Stoneskin when he sees the avatars popping. Requires very good reflexes but doable.
2) The BRD and/or the RDM (if present) can go out of range, like to the very edge of the arena. This will make one or multiple avatars chase for them and use their Astral Flow on them. This means the main pt (RUN+SAM+COR+GEO+WHM) will have less avatars than usual using Astral Flow, which gives a small chance to survive a third Astral Flow.
Edit:
One thing I forgot to mention.
Between the "Sleepga TC+adds" and "Dia to pull TC" moments, make sure you aren't too fast. You need to wait AT LEAST 1 minute, if not more.
That's because TC at start has a very strong Intimidation effect which slowly goes down as time passes by.
That's why you need to wait a bit and, consequentially, avoid silencing it too early.
If you do the above process too fast, you risk engaging a TC with an intimidation that's still too strong, making your DPS unable to gain TP through melee hits and hence critically slowing down the kill speed which, as I said plenty of times, is the key into winning this fight because you can't really survive all 5 waves of Astral Flow, u need to kill it before.
