GDI, Tiamat.

She keeps getting two attacks off before my mitigation is up. First time, it was "Rake the support user, then breath" a moment before my Shellga and Full Break went off, killing the breaker and leaving me without second-tier defenses. The second time, it was "Rake the white mage, then breath" between Shellga and Full Break, which was enough to kill Aerith. At which point the game was over, it was just a matter of how many rounds I could last before various Breath attacks killed me.