Ratio must be fuming at how L suggested he pretend to be the real Kira in order to direct the second Kira. Adding "you're the only one that can pull it off". Ouch! That was too funny. Sticking it to him in these subtle ways and seeing Ratio get inwardly upset is priceless.
It's interesting, so far Ratio's analysis of Kira appears exceptionally correct. That's only because he knows exactly what's going on. He is Kira. He's been able to appear effective on the grounds of his own doings. In this chapter, Ratio knows that the second Kira is fake, for obvious reasons. Knowing this makes me appreciate L more. He's been kept in the dark since the beginning and doing his best to work with what he's got. Impressive but I can't help feel that L was born with supernatural intuition, on top of intellect. If Shinigami exist, why not? Reading his thoughts, he sometimes goes off of feeling and builds information around these bouts of instinct. Maybe it's just an example of his experience with difficult cases?
These last few chapters have been exciting. The second Kira being so reckless and throwing Ratio and L off guard has kept the story compelling!