These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
The shenanigans involving Futaba's blood during the Tournament arc and immediately following suggest it was not entirely out of left field. According to later interviews, part of the problem was that the manga was canceled before the writer/artist was ready to finish it.