Luigi is the younger brother of Mario and is usually very timid around many people. He is in the shadows of Mario but on countless times has a burst of courage and fights.
In SMBZD: Two World's Fate, Luigi is apart of the main cast and is easily terrified of the lightining. Shadow then teases him about it. Luigi does well fending off Falco, even defeating him in the end once using both his and Mario's hammers.
Luigi has a wide range of transformations like Mario. as the two have done many on countless times. However Luigi does not display this until episode 3. See Luigi-Transformations for more details.
During the events of Total Drama Mushroom, Luigi was claimed victor of the competition after beating Shadow in the finale episode. Luigi is depicted as a sweet, cowardly and sensitive guy who cares for many and is smart and strong in the heat of the moment. A majority of Luigi's interactions with people are positive and he has made lotas of friends throughout the show due to being the winner so he was featured in each episode.