Both tfv8 cloud beast rba's that I have seem to be stainless steel coils. They work in the 18%-24% range of the xxx mode on my G2's and Slice. (That's actually more in line with the range for chromium. But I've never seem chromium used for coils.) If they were kanthol, they would be way down in the 3%-7% range.
The tfv8 baby coils are kanthol.