I've got an Int build in progress and just scored Big Hat's catalyst along with the TCC. I have my int at 45 currently (working up to 50max). I've been using this http://darksoulswiki.wikispaces.com/Magic+Adjustment to figure out what catalyst I should be using at any particular level to get the most out of my magics. However, once I had both the TCC and Big Hat's catalyst, I did a little comparison damage testing on the knights in Anor. I started out with homing crystal soul mass. Big hats did 627. TCC did 597. (I'm trying to remember the exact numbers from yesterday, they may be off a little but the jest is there.) Then, I tried homing soul mass. The numbers were reversed. TCC did about 640 and big hat did 591. Then I tried soul arrows and big hat out performed the TCC every time. I guess my question is, does the TCC produce more damage with non-crystal spells? Or am I missing something? I have searched high and low for a logical explanation of the magic adjustment mechanics of this game and I have come up empty. Any geniuses out there want to try to explain it to a noob!?
Im not sure about the numbers you scored up there, but the Tin crystalization catalyst is the best catalyst inthe game (if you dont care about the halved spell uses) and should do the most damage. The only reason i can come up with is that maybe the knights have more resistance to certain spells than others? Its a lowsy excuse but maybe try it out again to see if it keeps happening, i use the Logans Catalys and Tin Crystalization Catalyst myself and found the TCC out performed the Logans Catalyst everytime Hope this helps XD