This boss can easily be tanked by a melee DPS, allowing 2 melee dps and a healer. Trust me, with 2 MAs thi boss is a breeze. Also, vy the time a MA hits lvl36 or so, he can tank and dps needing only a healer, even using blue gears fortified until SS are needed. Put simply...tank on melee DPS and use a 2nd melee or ranged dps to bypass her m-att immunity and she will crumble.
The idea of using an illi is novel, but the illu will not be able to dmg her once she gets immunity, so a pdps is a better choice. even if she stacks one or two heals, the pdps will easily outdamage the heals.
Key to MA success - wait until bosses heal buff flashes and hits 3 secs - stun her. She will miss the buff and buff will expire, ths resetting stacks.
Stack resetting is a great skill to learn. In vileshark and trial version, axe moss has a stackable stat and attack decrease debuff(10% a stack) a good tank will be able to clear this by kiting, or by using stuns/ sleeps if the party has them. This applies to several other bosses as well.