Mithra learned how to speak from the villagers in the north near where he worked as a ferryman to human corpses and it was not until way later that he realized this way of speaking was extremely polite. He's never made an effort to change how he expresses himself, however. This politeness is a striking contrast to his real nature, which is uncouth, power-hungry and violence-driven. Mithra is constantly spacing out, mostly due to the fact that he genuinely doesn't care about most things.