Yndra are extremely powerful Demon Gods who have superior control over emotions. Each one uses emotions as tools. No one understands how they do it.
Khu' Kmau, Yndra of Happiness: Khu' Kmau's power comes from the happiness of those around him. He is the second strongest Yndra and often helps mortals. He brings happiness, thus increasing his power. He resides in a pocket Realm, built with his own power.
Kalmar' Dyodrida, Yndra of Anger: Kalmar's power comes from anger and pain. He is often interested in the affairs of mortals. He often kills mortals, in order to increase his own power. He does so slowly, to gain power from the pain they go through, he then sends a message to the victim's family in order to gain more power. He often gets into fights with the other strong Yndra. He resides in the underworld, where he gains most of his power.
Deziil' Na, Yndra of Sadness: Deziil's power comes from those who're depressed or sad. He rarely leaves his pocket Realm, as he can collect his power easily from there. He is one of the most hated Yndra because of the effect he has on people near him. He causes people to feel horrible, and is often attributed to disease.
Marn' Khorizza, Yndra of Love: Marn's power come from those who love others, or themselves. He has little power compared to other Yndr, as major wars have a major effect on his source of power. Since he's such a weak Indra, he does not own a pocket Realm.
Lo' Zizsa, Yndra of Emptiness: Lo' Zizsa's power comes from anyone who has either has no emotion or are full of emotion. In this sense, he is the strongest Yndra because both those with and without Souls can be used. However, he is also extremely dangerous and hostile, and will not hesitate to attack anyone who consorts with him. Instead of a regular pocket Realm, he owns a full sized Realm, due to the power he gains so quickly. Along with his regular sources, he also has tethers in the God Palace that let him sap the power from there. He could have been made a full God, if not for the fact that he saps power from the God Palace.