An asura can be like a deva — though some sources consider them as titans or demons, beings different from devas — and live more pleasurable lives than humans, though they are plagued with constant envy, pride and aggression towards others. Though they are also technically part of the sensuous world, they are classified to be in a different realm due to their state of constant envy towards the devas.
The placement of the asura realm in Buddhist cosmology varies among traditions. Sometimes the asura realm is recognized as one of happiness, existing beneath the worlds of the devas and humans. In other schemes, it is viewed as a fourth addition to the usual three evil paths that make up the animal realm, ghost realm, and hell realm.
Birth in the Asura realm is the result of performing good actions while harboring feelings of jealousy, envy, and pride. It is seen as a state where you are cultivating good karma due to your deeds but creating bad karma due to your intentions.
Due to the intense negative feelings that asuras are in thrall to, they are most likely going to be reborn in the three lower realms (animal, preta and hell) once they are deceased, although there is a small chance that they may reincarnate as humans due to good karma in a different lifetime.