Funny, I didn't notice the last girl in the Mermaid Heel until now.
Cool level is 6 & 7, currently only Yuka Suzuki has reached the 7th level in on of the base stats (his def is the strongest), though many characters have reached 7 in their personal stats ;P.
Rogue has higher stats than Sting, no wonder his skills haven't been shown yet.
Yeah Yuka has a powerful defense. Natsu managed to break through it but that's only because his a lunatic, but now it's probably on a whole other level.
I had a feeling Rogue was at a higher level, Lector just keeps bragging about Sting being the strongest.
And that last girl in Mermaid Heel was in the latest Chapter, she's most likely the second strongest after Kagura.
New chap is up, and its an interesting one!