Durren's CA is 12 at Lv1. Nimrook is always the best at any given level but Durren comes within a point of him around Lv20 and stays there until Lv40. Durren's CA tops out at 30 at Lv50 and then falls back to 24 by the time he's Lv99.

Miyu is a much better choice.

The free agents I recruit are always Shaami, Kiyuri, Ropp and Naida.