Kishi ignored madara's MS abilities because madara was already too hax. If they gave him an ability like kamui, tsukuyomi, or amaterasu, he would've been unbeatable....not to mention perfect susanoo, wood element and what not.
Probably the same with izuna. Izuna needed to die because um.....plot. If he were truly as strong as madara (which the manga clearly stated) then it would be the same problem. Simply too hax.
Probably the same with izuna. Izuna needed to die because um.....plot. If he were truly as strong as madara (which the manga clearly stated) then it would be the same problem. Simply too hax.