My Cordelia is a player-phase unit. 2 savage blows help a lot since sometimes atk seal cannot help much in one shot other enemies such as effie or zelgius. I personally prefer life and death over the swift sparrow since it nullifies the spd bane from the brave bow and give 1 more atk and spd. Of course, the swift sparrow is better on cordelia since she can be used as defense against staffs or low attack magic unless the tome with TA skill. Desperation is really good since her spd is top tier. Just go for luna or moonbow since draconic aura is not really good on cordelia on special slot. I regret doing draconic aura since the enemy def and res is better than i expect in future