Board Thread:Naruto Discussions/@comment-27296281-20170721061114/@comment-734582-20170721143629

GreatestSin wrote: as you said "plot", thats more or less the sole reason... The entire series is plot. Doesn't stop us from reasoning and theorizing what the author intended.

It's clear that TSB's aren't just regular nature transform orbs. They appeared when characters awoke certain powers, without further imput. So whatever they precisely are, they're not just orbs.