The DEF Paladin

While replying to another thread, I recalled a guide made by a 12x WK in the pre-4th job era. His thing was raping DEF scrolls to make his character invincible, to the point where he could train on monsters way too high lvl for him, AFKing in high lvl mobs and saving a huge amount of money on potions. While now 12x is not high lvl at all, back then it was. With Power Guard, Achilles, Shield Mastery and equips scrolled for DEF, (I am guessing the cape could be a Pink Gaia instead of DEF,) could such a character cut it in Leafre or Neo Tokyo while breaking even, (drops compensate for pot costs,) and lvl fairly efficiently? I am not poor, so I don't have to make such a character, I am just wondering in theory. Also, what build do you guys think such a character should have?"

Thanks!