<p>Well personally I don't really know if this would qualify as a dojutsu but if I had to create one it would be one that hybridizes the Sharingan, Byakugan, and Rinnegan. The eye itself would look identical to the sharingan (that is a red iris and one to three tomoe as ones use, skill, and chakra control develop) but with one key difference. Once had developed three tomoe each would act like a gate. Each gate would hold one of the Three Great Visual Jutsu. For example if the situation called for the sharingan one could activate the respective tomoe.
</p><p>another potential candidate would be a dojutsu that allows one to use any of the seven chakra natures (fire, water, wind, lightning, earth, yin, and yang) in any combination that would be not result in contradictory results. We've all seen shinobi with Kekkei Genkai use two chakra natures at once (Haku, Roshi, and the former Mizukage to name but three examples) and two that can use three at once (Onoki and Mu both using Particles Style: wind, fire, and earth styles) called Kekkei Tōta. My idea is merely an extension of that but without needing an inherited Kekkei Genkai to do so. for various combinations of chakra natures consult the following (url:
http://pre11.deviantart.net/6dbf/th/pre/i/2012/276/5/b/elemental_combinations_2_3_by_fg7dragon-d5gosiu.jpg)
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