I have to admit, that kind of approach isn't too far from what was probably intended.
I tried using him in a Big refess/ Marduk style (Starmanderless), and have to say he is not BAD as a tank, since he can downright null certain units and hold the field as a sort of "Anti-iczer" unit, but he still spectacularly fails (relatively for his level) against anything that can either null defense or surpass it, due to relatively low HP and abyssal slowness.
And his disengaging counter, while useful on a fast unit like thorned battle diva, is almost useless on a unit with -7 agi unit with 50 def (Granted, it is most certainly intended to be used for his start skill). On the other hand he is the first refess unit that can properly kill those pesky Battle Kesaran Pasarans that are overwhelming Folrart since their arch-enemy, the Battle Owl sage, has been nerfed to uselessness.
All in all I'd say he is OK for some matchups, but utterly fails in others (I'm tempted to say "most", but your mileage may vary).
On that note, why exactly can a unit get -7 agi? Or any negative amount of agi for that matter?