This page is from waaaay earlier (by almost 150 chapters) so the translations are probably slightly inconsistent, but basically Rakan is the Knight type (swordsman) of apparently Light type (but he's well rounded apparently) and Nagi was a Light Magic Swordsman.
EVA said all the way back then that she thought only Magic Swordsman or Traditional (offensive) were suitable styles for Negi. Rakan brought up how Dark could possibly suit him more than Light.
So it looks like Negi has already chosen Dark Magic Swordsman.
So what the heck is "Telepathy Support?" An enhancer? And "Intelligence Raider?" Some sort of commander?