Asuras are devs who have a faulty connection with the sun and moon. They were either born this way from other asuras or were cursed. They have blemishes that do not change color like the rest of them do. Asuras do not have any light magic capability at all which is the main reason they are looked down upon by other devs. Most also suffer from a 'cursed time', a time in the day when they suffer from an ailment. The time of day and ailment is different per the individual. As part of the prejudices against them, asuras are not permitted to live in dev populated cities. Those who work in dev cities doing jobs that devs consider beneath them to do, are required to cover themselves when in the presence of devs to hide their 'ugliness'