Vishnu is the Lord of protection, sustenance & maintenance. His consort Lakshmi is the possessor of wealth, which is a necessity for maintenance. Goddess Lakshmi represents not only material wealth, but the wealth of grains, courage, valour, offspring, success, luxurious life, eternal bliss. Vishnu and Lakshmi thus help the souls introduced into the life cycle by Brahma to survive in the cycle of life;

Lord Vishnu is also called Nilameghashyamalan - possessing a complexion the colour of the dark clouds. As proof that opposites attract, Vishnu's outer appearance is dark while he is associated with the santha gunam, bringing light & peace to the world.
VISHNU
He rests on the ocean on his bed of Adisesha (serpent with 1,000 heads). Any time Lord Vishnu sees great trouble, He takes an avataram to rescue the people from evils. He is all merciful, ever rushing to serve his devotees.

In the form of Mahavishnu he has four arms wielding the chakra, conch, lotus & the gadha or mace in his four arms. Some of the main avatarams of Vishnu are enumerated as the Dasavataram (10 Incarnations).

Dus Avtar Of Lord Vishnu..