Saber (Fate)
Iron Man (Marvel)
Saber (Fate/stay night)
Saber (Fate/Stay Night) without a doubt, if she doesn't fight Clare (Claymore).
Morgiana (Magi) maybe can be another alternative but i'd rather have her fight Sakura from Naruto.
Iron Man is a terrible idea and would at most work as a DBX.
I thought of Varian but I prefer him against King Bradley from Full Metal Alchemist.