I'm glad that the doctor guy only wanted Shioon's blood, though I'm curious what his plans are for it. As for the pill, I don't think it's a bad development at all. "Take it 30 minutes before the match" means "this is temporary." Any type of snap fix isn't interesting, so yes I'd expect it to have some nasty side effects, but I also expect it to be worth doing in the end. So, as a result when it's all said and done I think Shioon's Ki center will be 99% destroyed instead of 100% destroyed like it was before, and then his black origin threashold breathing techniques can restore it slowly over a large amount of chapters, or something like that. That idea seems like a solid basis for story writing, at least.
I do still think about the phoenix cry technique thing being possible, but I think such a thing would be better used once his ki center was already starting to come together later on, if at all. Until that happens, though, I'm willing to write it off as me being wrong about the idea, and I credit the author in choosing a more gradual solution to the problem either way. I suppose I was thinking impatiently about it as a reader.
Shioon is going to totally plaster Changho next chapter, most likely, so the fight alone isn't interesting. What is interesting is that the 30 minutes of running put them heavily in the public eye with the police about to be called to boot. The title of "The Breaker" could finally start to take on meaning now, with the SUC being guilty and Shioon as well by extension. The leader guy in the car can't really afford to show himself or his cover will be totally blown by Shioon, so I'm not seeing him stepping in as a very promising plot point.