Instead of more water bending favoritism bullshit.
I mean, is it really favoritism, or is it just science? Humans have a lot of water in us. We're mostly water. All our parts, without water, would basically be a pile of dust.
It's not favoritism to give a select few exceptional benders the ability to manipulate blood any more than it's favoritism to give metal bending to earth benders or lightning bending to fire benders.
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I write Naruto Fanfiction. But I am definitely not a furry.