Okay, so there's still some things there that need more clarification or... don't match properly? For one, none of the groups involved would have accepted an unrelated mage joining the knights to judge the captain. Like, the nobles want one of their own there, the king is currently backing the knights, and the college is independent of royalty. And it's too obvious. Basically, the nobles would send someone to join properly who actually has military training etc. to undermine them that way; it's not like an independent inspector. On the other hand, the knights [i]should[/i] have someone magically proficient around, so they could ask the college that way.

Speaking of the college, 

Secondly, minor point: mana isn't made of particles. More of a pervasive (and coloured by person) glow (more wave-based than particle-based to observe). Though that's just a note.

On the abilities section, apart from not seeing why you would need to be strengthened to use particular magic (why would it be stressful?), you're going to have to give some example of what you [i]mean[/i] by powerful mage, so we can all get on the same page on how strong that would be in-setting?