Cloud was just a kitten when Patrion pulled him out of the river, where he had fallen while playing. Since then, his loyalty to his savior has become indestructible. Steely claws and a feline resilience are his weapons, which put together with Patrion's skills make a deadly combo.
Mishka was created when Cloud was playing in a field and accidentally stepped into a portal to the Underworld. He immediately got out, but Mishka took form from a couple of his cells that were left behind.