Avatar: The Last Airbender

My pointless head cannon: Aang the Bloodbender

Aang was good at picking up waterbending from just watching, even if not enough to be a master easily he could still do it. Aang totally picked up bloodbending, or at least thought he did. The idea is not hard to get to once you've seen the premise, and Aang both saw and felt the premise in the fight with the puppet master (blanking on her name).

So why doesn't Aang seem to use it or even know it? Katara. Aang knows Katara wants the practice to end with her so he never tries it, never practices it, never even acknowledges it when he can avoid it.

But I would be surprised if there wasn't at least one moment, one fraction of a second, where Aang didn't look at the full moon and think, "I could. I won't, but I totally could."

Let me be my own critic here and point out the obvious: Bloodbending is a seriously advanced technique that takes a good amount of prior knowledge even for a master waterbender like Katara. Aang doesn't have this prior knowledge. Also there are some techniques Aang just doesn't bother with, like the swampbender's plant bending, so he could have just ignored bloodbending.

But come on! The Avatar saw and understood arguably one of the strongest bending powers and CHOOSE to not use it out of respect for those around him? That sounds so perfect!