For wife he has the spirit of the clouds and waters, Apsaras, and by her became father of the first mortals, Yama and Yami.
Mortals need the power of reason to deal with us.
No. But mortals shouldn't travel through the shadow world.
Mortals can be killed by anyone. Immortals can only be killed by other Immortals or demons.
Serpents were supposed to know of a root which brought back their dead to life, and an old Greek story told how certain mortals took the hint.