Look at it this way: Yujiro is a demon. He has spent his entire life since the moment he was born as The Ogre and has never once deviated from that path, and so every part of his body is demonic. But Baki? Baki was born as a human, with the blood of The Ogre flowing through his veins, and so in addition to becoming stronger and bringing his body to the level of a demon, he needs to attain the right mentality and begin thinking like a demon to truly equal or surpass Yujiro, and we've seen hints of this as the series has gone on, especially after Baki achieved the ultimate post-nut clarity. He still slips up of course, like when he got rocked by Oliva and Guevara for getting in the middle of their argument, but then you see him go back into that when he's laughing at Oliva for his decadence and arrogance chaining him down, and when he gets incredibly excited at the prospect of fighting Oliva in a man-to-man slugfest and overpowering him through strength and determination rather than skill in martial arts.
