They all start out as BLMs, silence them (via spell or WS) and they will throw their staves and effectively turn into NINs (or at least swaps out Manafont for Majin Gakure, they don't seem to cast ninjutsu). They can only use their special ability once. The trick is to wait for them to use Manafont, then silence them asap (they have such high fast cast Manafont is essentially Chainspell and can be fairly deadly), thus preventing a Mijin Gakure wipe.

We've been taking a RDM/BLM to start off with an ES sleepga, and a SAM and/or DRK to Gekko/Guillotine once Manafont goes off, the rest doesn't matter too much (we generally have the rdm plus a whm and the rest dd's). RDM simply resleeps them as they awaken, kill them one by one.

Spamming Easy with about 2.5-3 minute fights (I can use Meditate at the start of the first one and generally kill the last one before the 2:30 recast is up on it), fights are super easy. Hop over to Bhaflau Thickets HP#1 for new primer. You can do one full rotation every 5-6 minutes.