1v1 build until level 100:
xxx str 40 sta 50 dex. Works perfectly.
After level 100, i went full Str nothing else, because mobs start to hit shit on you, i mean i was able to tank 10 mobs at full str lv 110 ( No i did not fight like this, it was just for fun i did it once rofl

)
So.. you wont need sta after 100. thats already been proven by what i just told u.
Dex. The only reason a blade needs dex is to get the 96% Accuracy for maxmimum dmg out put.
please remember that high DMG Per sec is better to have then high dmg.
For female blades, getting 96 hit is easy. Shaentra boot, and +8 dest for guys, its gonna be harder. 10 Dest set.. >.< Kinda more expensive then the female lol.