Alex is a character from the doujin(fan-made) fighting game "Super Cosplay War Ultra" (ironically). The characters look semi-chibi-ized. What makes each character different, though is that for each move they make, they don costumes from the series of their choice (except Sin, who dons costumes from a movie series). Of the series represented (among them Naruto, BioHazard/Resident Evil, Hunter X Hunter, Astro Boy, Totoro, Evangelion, Getter Robo, and .//hack, just to name a few), Alex's series is "Kyoryu Sentai Zyuranger" (a.k.a. - "Mighty Morphin Power Rangers"). To see how it plays, there's a vid here:
http://www.youtube.com/watch?v=hqHBf1_wa_0

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