Denis became vegan in 2017 after learning about the grim fate of male chicks in the egg industry. This led him to commit to fighting against Animal Agriculture right away, and he has since devoted himself to promoting a plant-based society free from all forms of exploitation.

During the COVID lockdown, Denis immersed himself in Animal Rights, Veganism, and Climate Justice, reemerging with a renewed determination to educate and motivate others. Since December 2022, his activism with Sentient Rights Ireland has demonstrated his dedication to ending speciesism and advocating for ethical living.