I Get Stronger and Stronger by Eating

The world collapsed, and a hole appeared in the sky of the earth. The pestilence swept over the whole world, and humans built high walls to protect themselves.
Roddy was expelled from the city after being infected with the virus. Just when he thought he was going to become a monster, he found something had changed inside of him.
After eating the mutated creatures that had been infected with the plague, they would become stronger!
In order to survive, Roddy started a meal!
After chewing the cannonball ants, he gained a hundred times of strength!
After eating the ghost-faced fish, he obtained the power to breathe in the water!
After biting the crypt demonic spiders, he got the spider radar!
After swallowing the forming judge, Roddy became a god!