You know, I can't be 100% sure, but I remember my brother and I got Sasuke's Armor from a mini-boss drop on one of the higher floors, I THINK. Not 100% sure it was the armor though, but I feel like its worth a try if you're really determined. Hope I can help you out man. Keep up the determination. (So I'd try bombing high level hallways if you haven't tried them all)
...wow...I am Jack's Colon...theres a whole series of these.