I like that this shifts him from a climactic surge of power and confidence with many rough strokes to simplified and somewhat hollow line work. This helps to play up his vulnerability as he's tossed around by the giant. When he formulates a plan and fights back I begin working in color and shading.
Up until this point very minimal color is used with particular attention to red. So I use a good deal of red in our character's color palette as well as the overall color script. I'm not as well versed in color theory as I'd like but I am trying to use it to help convey tone and particularly the shift of tone in the fight sequence.
Going back to my mood boards...
I'm particularly fond of the climax in the animated show FLCL. I like the use of intense reds, oranges, and yellows so I bringing that out a good deal. I'm also using somewhat adverse colors to fill out the giant and make him stand out as the antagonist.
This is the rough climax color script I'm working from:
I was initially gonna take these thumbnails and use the exact color in toonboom but I've found that I really gotta work with the color more as I animate to get the most out of the color choices. It doesn't help that the palette changes from shot to shot but I think the overall effect will be worth it.