Shinryu (Final Fantasy XI)

Shinryu is fought as a Notorious Monster in Abyssea - Empyreal Paradox. He is the final boss of the Abyssea story line.

Abyssea - Empyreal Paradox
Shinryu is encountered in the last mission of the Abyssea story line, "The Wyrm God." He is quite massive and has an array of strong abilities at his disposal. During the fight, his HP cannot be seen unless he's using a certain TP move, and he changes "stances" every 2-3 minutes. While it is possible to solo Shinryu using a Primeval Brew, doing so contains risks.