Quote Originally Posted by Dragonlord View Post
http://ffxi.gamerescape.com/wiki/Angon

Angon's defense down, dnc's box step, and dia's defense down all stack. I guess it depends if add.eff from weapon and WS count as the same debuff. Probably /shrug
That's because Dia inflicts "dia", not Defense down, Box step inflicts "Sluggish Daze", and Angon inflicts "Defense down".

It's all about the name, not the effect. (With the apparent weird exception of cruor buffs and Boost-stats)

Both the katana and the polearm inflict the same named effect, so they wouldn't stack, though both would stack with Feather Step. (Because it inflicts Bewildered Daze, not crit evasion down).