Default right after he turns it off too because you would get pwned otherwise.
BRAVE AWAY ! Hitting fast and hard it the key since he'll soon put up his shield again. I went with Spellfencers, a black mage and a healer. I thiiink he had a weakness to an element but can't remember.
Don't forget to heal heal heal overheal.
And you can poison him too ! Which takes a good chunk of his life every turn.
I must have been overlevelled because I absolutely decimated this boss.
Examined to get weakness. I saw his shield so I knew something was up. Defaulted until transformed then I bombarded him with every high powered attack augmented with lightning. I was getting like 7000, 9999, 9999, lol ...