As I was running out of time, I decided to use one of the antagonist's poses from the posed character sheet, and a similar pose for my protagonist to one of his poses in his sheet. Overall I like that the look is a little cartoony, it combines DotA 2 and Bob Rafei's styles decently, with the subject matter as well as the cartoony elements. I feel that I could have experimented more with proportions and styles to create a finished look that reflected all three styles.
I originally wanted to have the protagonist lifting up the earth or rocks to form a shield against the beam, however, after doing the posed sheets, I settled for the shield. My inspiration would have been taken from the Earthbenders in Avatar, perhaps some scenes in Naruto, and a scene from Full Metal Alchemist during the episode Miracle at Rush Valley, for which I cannot find screenshots for.
Below is my idea for the background, however it was just not looking good or flowing, in my opinion.
Here I deliberated between the two, either having a simple beam or the more exaggerated one, and after asking a friend he suggested the latter. I think it adds more to it, but I am not completely sold on the style. With more time I would refine the beam and the shield, as I was having quite a bit of difficulty getting them right along with the perspective. I tried to gather some reference images but they were not helping too much, so I guessed to the best of my ability.
I also decided on this background as I wanted some terrain so it didn't look so flat or odd. The sky came about because originally I wanted to do water but no matter what I tried it just did not look right at that angle, so I painted a flat colour, which was a green/blue colour, almost teal, and then painted over with a yellow using a brush that was perhaps for cloud effects. I really liked this however I felt that there was just too much colour with the bright orange and purple, so I decided to darken it, and that really brought out the highlights for the antagonist, but I still feel the design, and therefore shading, on the protagonist is lacking a bit.