Free Step Dodge

Probably go with a no and a maybe. Mostly towards the no seeing as Sega would probably still ask TN to design similar characters if it came down to it and diversity either way (maybe). Even if Sega bought TN, DOA is owned by Koei Tecmo despite TN making the series. (Unless you mean an entirely new fighting game then that could vary).

Course this is just an opinion and mostly a guess that I might be incorrect on, but I don't think Sega would make much of a difference when it comes to design or character diversity, but eh I might still be wrong.

I'll tell ya what would happen if Sega would buy both TN and Gust. We'd only see Atelier and DOA games until Sega dies completely or goes bankrupt. To answer you question though, think that there wouldn't be too many changes when it comes to the designs of the characters or their diversity. They'd probably become less revealing (you know what I mean) maybe.