One of the most prominent theories about Tadashi is that we will see him returning as Sunfire, one of the original members of “Big Hero 6”. Apparently, the character has undergone a transformation that brought him into his new state.
Sunfire has the special power of absorbing heat and transforming it into plasma, a skill that’s obviously come in handy a few times. That could have some interesting implications for the storyline if we’re going to see Tadashi returning in this form.
It’s not yet clear if he’ll be a good or bad guy if this happens, and there have indeed been some rumors that Disney might want to make him into a villain for the sequel. While that’s certainly an interesting idea that will shake up the plot a little bit, not all fans are seemingly on board with it.
Some have expressed disappointment towards this rumor, and are claiming that the story will take a turn for the worse if Tadashi is portrayed in such a way. Of course, we don’t know anything about the overall plot of the new film, and for what it’s worth, such an idea could actually work very well – we’ll have to wait and see what Disney might be planning.
I believe it should be called Big Hero 6.2 or 2 Big Hero 6, or Big Hero 6 with a subtitle.
It’s called Big Hero 6 because there’s 6 of them, why would they call it Big Hero 7