Is this a possible reason why Orochimaru isn't stronger than Itachi anymore. I am not sure this is accurate timewise, but is it possible that the reason why Orochimaru is weaker is that the body transfer technique imposes weaknesses on the new body. It seems that the body degradation of the technique itself are pretty severe in the latter stages, and might be pretty crippling from the onset of the technique. It seems stupid of Orochimaru to use the technique in the first place unless somthing happened to his body.... A possible reason why I think Orochimaru used it in the first place was I think his original body was crippled severely by his last fight with Jairiya. So prior to this point he was stronger than Itachi, but after the fight perhaps he was forced to change bodies because his old body was too damaged by the fight. The reason I think this is because the whole body switching thing at this point seems useless because from the beginning of the techniques use, as the person get weaker and weaker (as specified from the manga). Why did Orochimaru use the technique in the first place if it would only really handicap him. It would be a lot smarter to just use it when, he is ancient and old, so he could really use the benefits. The reason why I thought of this explanation is it would explain how Orochimaru could be considered stronger than Jairiya at one point, and why Itachi semi fears Jairiya right now(as Jairiya is just as capable as he was back than, while Oro knowing the sideeffect of his original technique knows he could be weaker than Itachi). Orochimaru is pretty strong from what we seen, but he doesn't seem much stronger or better genius wise than the rest of the sannin in techniques, from what Sarutobi thought of him, it seemed at one point he was heads and tails above all of them.