Although the main "centeral" character will be the female proanganist, "Lightning", Kitase annouced that they will not be a main character in Final Fantasy. All characters have equal parts as the NES Final Fantasy III (VI US verison) had.
Kefka and Ultimecia are two separate villains from two separate games Kefka is the main antagonist of Final Fantasy VI and Ultimecia is the main antagonist in Final Fantasy VIII.
No, characters from the different 'main' Final Fantasy games are not related to the ones in others. They are totally different worlds and universes.
There aren't any Mario games with final fantasy characters.
It depends on what RPG you're playing. In a RPG like Final Fantasy, the highest limit of characters has been 5, shown in Final Fantasy VI. Other RPGs have their own system, and can limit characters.
The main villain in Final Fantasy VII is Sephiroth
Yes, Tellah is the only real "main" character that does though.
Final Fantasy 7 did not have sprites. It was the first Final Fantasy game in which the characters were rendered in 3-D.
The main character of Final Fantasy V is Bartz Klauser.
Everything (from characters to story line) in each game of the Final Fantasy series has little or no resemblance to its predecessor.
You can play as characters from multiple final fantasy games (though not all) in games such as final fantasy dissidia 012: duodecim.
The main villian in Final Fantasy 7 is Sephiroth.