Madara GNW is a bit squishy. even using all the rows to try to mitigate dmg coming to him, I've experienced half his health gone even with fire main shield after round 1, in arena many times. Madara GNW is much better paired with edo Nagato (BT) so that he gains immunity when shielded, and will be even so much better when his BT is released (grants himself and all ninjas in his vertical row super armor).