I have the game so...
Ike is the main character in most parts of chapter 3 and some of chapter 4. any by the way who ever said Ike was a bad guy... well
in chapter 3, part 13, Ike is the enemy boss. He is very tough and you should turn away when he starts move.
Then in part 14 in chapter 13, You play as Ike again where you have to face the dawn brigade
no matter what anyone says, Ike is still the main character and ends the game so I think he is