I'll see if I can help.
- Typical SMN opener on Boss + Sprint to get the Miasma II off without any down time. (Rouse/Spur/Enkindle so Enkindle will be up on the second set of adds)
- I usually Ruin II to get a Fester off without any GCD downtime, but in this case I don't. Mainly because I want to conserve MP for when I need to use R2, i.e. moving in for Charge, Tethers. Because of that and the tempo of the fight I time my Festers with the re-application of Bio (2 per Aether Flow), or take the small DPS loss of using Fester after a GCD.
- Adds, Shadow Flare in area of 1st set to kill during Electrocharge. DOTS + Bane (should have 1 aether left) - Aerial Slash
Then I move to the other set of adds, DOT, M2, Contagion the Sister, Bane and I leave Garuda on that sister (Aether Flow will be back just after Dotting). Then move back to the 1st sister/brother. You should get a single Fester off on the sister while dots are up, then I move to the brother and reverse Dot (Bio, M, B2)
Then I go back to the 2nd Set Sister, SC Shadow Flare and Ruin spam until the Dots need to be reapplied, then Bane them to the brother and start attacking the brother.
- Shadow Flare, DOTs, Bane, Rouse, Spur, Enkindle on the first set to attack then LB
- DoT and Bane the 2nd Set
- DoT + M2 the 3rd set + Contagion the Sister - Bane - Leave Garuda on the Sister (Aerial Slash etc). SC Shadow Flare
adds all die
Then just burn the boss down in the last phase, using whatever you have left. Even if you have 200 MP at the end you can still cast stuff
-------------------------------------------------------------------------------------------------------------------
I think a lot of SMN just blow their Aetherflow on Festers instead of saving them to Bane more. For fights with many mobs that will live through multiple sets of DoTs it's better to just toss your dots on them and Bane. Bane is much stronger than Fester even with only two mobs and is a key skill for MP conservation.
Doing a Second Bane VS using Fester (2 Mobs)
Fester 300 Potency - 0MP Saved
Bane - Spreads ~800 Potency worth of DoT Damage - 401 MP Saved (Savings compared to if you had to cast the DoTs a second time)
So a difference of +740 Potency with a savings of 132 MP, (providing you cast Ruin three times VS having to recast your DoTS on the 2nd Mob) by not using Fester and using Bane to reapply DoTs on extra mobs where applicable.
--------------------------------------------------------------------------------------------------------------------
MP Conservation is the only mechanic that SMN seems to be effected by, compared to what other classes have to go through. That's only on a few fights as well. I don't think it would be fair to other classes to change that.