Cannot beleive i didnt see this thread til now... at khmer, yes he does change when you get about half way or 2/5'th through the game (if no1 has answered). You can always just replace him with Asch using a bug/glitch.... (hopefully u know who he is by now). Same tech's but Asch as a few spells as well as different catch phrases and specials.
Also, Luke's beserker... how everyone saying its hard... it isnt.. hard mode is nothing compared to the higher ones... all that really happens is they have more life and do a bit more dmg :3 nothing you cant avoid or block.
You gotta wait til u get farther... Luke's final solo battle
= best fight in the game...
If you really liked Abyss characters, go ahead and get Tales of the World, Luke and Tear are in it... as well as Llyod and Genis from ToS and many other