Siren.....

[kukurumei]

Pretty much this. At first the fight seemed almost impossible to me because of a variety of things. This fight becomes incredibly hard for the healer if:

1) No one runs to the middle when she does her mass curse
2) No one stuns Lunatic Voice, the healing debuff
3) The dps is too slow in dealing with adds

Any of those can make this fight annoying, and it just gets impossible if you have to deal with all 3. Otherwise, if all 3 of those are taken care of this fight isn't bad.

Actually the opposite, while, silencing the healing debuff is nice, given a choice between being rushed, or healing debuff, I would take the debuff.

Siren will spam the lunatic voice anyway at around 25%, so no amount of silences can catch it.

I would say you can live through the healing debuff, you can't heal through the rush (towards the end).

You only need to esuna/leech 2 members (the tank and the cursed one) the other members can let their debuff wear off, and still finish the fight.

But absolutely do not get hit by the rush and you can probably brute force it to a win.

If you want to be cheap, bring a brd and ballad and start spamming aoe heals towards the end >50%. You can heal through the debuff with enough mp to win the fight.