User blog comment:Holokami/Faraday Isles Psychic School/@comment-26362471-20160312215925/@comment-26993961-20160312224639

A mix of both I believe, since the higher the Challenge Level, the more powerful you are, but a Telekinetic and Clairvoyant can have equal Challenge Levels.

The increase in PICT grades is nonlineral as well (likely logarithmic); The difference between C and B is greater than the difference between D and C. So even a difference of 1 in a Challenge Level can make a huge difference.

As an example, Bridget Morgan, a CL of 23, would be an absolutely terrfying opponent for Lucia Minniti, a CL of 10.

Hope that helps. ^^