Take Lelouch/Light, make him much nicer/more sociable, have no random superpower, actually go for girls and lower the scale of what he wants to change exactly and you get Yamato!
But yeah, Yamato is one of my favorite VN (and any) protagonists. Unlike many who are too dumb or dull, Yamato is a genius, and this makes many character interactions and events really great.
In a school where the average female is stronger than the average male, Yamato makes up for not being psyhically strong by always having great entertaining plans for the big events. Every so once in a while he can outsmart a really strong opponent just by thinking up great (and funny) ways to win.
It's hard to pinpoint which plans of his are my favorite, because really he does so many and pretty much all of them are great or at least entertaining.
And his hermit crab obsession is great as well.
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