Well, as far as I've gotten;
Arden is actually good, and probably Lachesis's best pair. >_>
Ethlin is a beast with a Slim Sword. She got to level 10 in Chapter 1.
Azel is a losing hope. <_<
Midir is pretty good, but having trouble keeping up.
Noish is decent.
Lex can decimate almost everything.
Cuan has been nerfed to almost sucking levels. >_>
Just a tip to people. Give Aideen Diadora's Aura, then in Chapter 6, capture Isaac. Aura, and Resire!