Greg has spoken about Gewdla online a few times through out the years. The oldest recorded instance was on his 2004 website Ziogi. On the site, he had a section dedicated to Greg's "Ziogi Dictionary" for words Greg made up. One of the definitions were for Gewdla: "Name of a "Negative Spirit" who claimed to invade the bodies of many others on this Earth. Also stating that it admired the creator of Ziogi, which was rather unwelcome. (1999)" (Source)
In 2005, Greg wrote about Gewdla again on his Onision website. There was page on the site titled "A Life's Story" where Greg shared important stories from his life. One entry was titles "Met Gewdla". (Source)
Years later, in 2017, Greg made a Speaks video dedicated to Gewdla titled "Meet My Imaginary Friend: GEWDLA". Greg starts the video by explaining when he was younger he thought he could talk to a demon. He says when he was a kid he was playing with an Ouija board with his cousins when a demon came up and said they had a specific interest in Greg. He says he asked the demon to possess him because he was a weird kid. He said he eventually made a photo manipulation of a picture of himself to represent the demon.
He says when he was at an event in downtown Tacoma he felt his legs were walking on their own. He says he assumed it was the possession, so he'd say "faster Gewdla" or "slower Gewdla" and his legs would walk faster or slower based on what he said. He says if you're a functional adult you'd know this was absurd. He says his legs were operating on unconscious motor function and Ouija board have been proven to be fake. He wasn't actually talking to a demon. He says he wanted to share this story because he thinks people don't understand how delusional our minds can be when we were younger. He says a lot of us lived more in a fantasy back then. He doesn't believe in demons or angels anymore because it's more productive to believe in the world around him. He goes on about how people can't prove they're talking to Jesus or a demon so they're probably suffering from an imbalance in their brain. ($ource)