Lvl 60, Monk.
Normal mode, MP0
Blade FOUND today.
Even tried dual wielding 2 blades.
Tried achievement TWICE today. TWICE!
First time, blades were equipped and he didn't give it to me. I also had gear on, (minus any attacker takes ### dmg). Killed him in one hit.
Second time I found him, 5 minutes ago, I had my friends join the game, we all took turns bashing the bashiok out of him with nothing but the blade so help me god. (single handed).
Still no achievement.
NOTE.... if you look at the Blizzard notes for BUGS in 1.0.5: http://us.battle.net/d3/en/forum/topic/6369438018
It is possible to not be able to receive the “Bashanishu” achievement if you hit Bashiok using a Basic Attack (not a skill).
^^^ What kind of sentence is this?!?!?!?!?!?!?! Are you kidding me???? Since the GOAL of the quest is to "hurt him with the blade" what kind of fuzzy logic are you using to make this statement? The sentence, clearly, when you put two and two together, should say "It is not possible to get the Bashanishu" achievement.
Its that simple. Fix it.