For the pants I am using YoRHa Type-53 Breeches of Fending but you can't really see it as the armor and the boots are covering it, and that is not the issue in the first place. Use literally anything you feel that fits or gives you a good vibe, I just went with this one. Just like my previous one, Dark Knight Abyss, this can be equipped by everyone so long as they are of tanking class.