When summoned, he will say "Sorry I'm late, I had other things to do.", before attacking enemies. When he is about to leave, he may either say "Hmph." or "I'm done, good luck on your side!" before leaving.
Magnus is perhaps the mightiest human warrior, and he has weathered countless battles. He seems to prefer working alone, and he can respect the strength of foes like Dark Lord Gaol. However, he seems reluctant--not afraid--to fight Gaol. Is there a connection between these two?