What is your favorite ultimate ability for that class?

A level 23 Mage with Combat Archery is quite rare. But if a Knight allowed him to get it, it's his own fault for not attacking earlier. Knights aren't the best at street fights, unless they've trained a bunch of monks. I train them against the AI. And with people, we agree to have the final battle in an open field. If there are more than two of us, we have a round-robin tournament – everyone fights everyone else. I don't level up Combat Archery for either the Knight or the Mage. For the Knight, because it's not very effective (in my opinion). For the Mage, because it's hard to live without magic until you get Combat Archery. Although Combat Archery is good because instead of magic schools, you can level up something else. And in the campaign, my Zephyr, with Sympathy and his native magic schools, easily defeated Biara without Combat Archery.