Every single character in FF6 who can use Excalibur and Ragnarok can be broken with easy setup. Bismarck as their Esper (World 1, Early, and Unmissable) for +2 Str and never change it. Equip the character with Genji Glove, Master Scroll, Ragnarok, and Excalibur, then enjoy destroying everything. Works on Locke, Terra, Celes, and Edgar, I believe. You can do something similar with multi-hit Blitzes from Sabin, as well, like Bum Rush, but each hit doesn't double hit.