You know the Manwha is not based on that Guy's ability, so calling it is based of on that is rather...wrong? He has a "Gaming Ability" while there are tons of people who don't have that. Which brings me to the point of the post to help you getting more inspiration, the author took a friggin lot of inspiration from Mabinogi(The "gaming"-ability is so based of on that), heck, he even drew Ferghus in one of the chapters xD, so you might wanna look into that too!