Oscar by KO. Castillo wasn't a great fighter, he was beaten soundly by few non-great fighters too (when he was in his prime).
That isn’t true. Corrales is the only arguable non-great who beat him in his prime, and he arguably was great.
Jauregi stopped him twice. Others stopped him too. Maybe you refer to Castillo being pre-prime, but there's no evidence that Jauregi couldn't do the same against early 00s Castillo
Oscar was very, very formidable at 135. Big, fast, skilled and very powerful. Castillo was a good, solid tough fighter but he never showed the elite qualities at Lightweight that Oscar did. I reckon Oscar wins this probably late inside the distance. Great match up though.
That's insane. Castillo's prime was from 2000-2005. He was a fighter who learned on the job. It doesn't matter what he was doing in the mid nineties.
Castillo might lose a decision or get stopped on cuts. He'd stand a good chance of finishing if John Molina and Miguel Angel Gonzalez could.