A/N: which one of these two dragon looking pokemon can outdo the other.

Austin: from a gaming stand point, it would be hard since Ultra Necrozma and Mega Rayquaza have similar level of states. Albeit, Mega Rayquaza has a big higher ones.

Kinda hard, But I think rayquaza might take this, give or take Necrozma doesn't attack first.

 From an Anime Standpoint, Mega Rayquaza has an advantage since the anime showed how well he's able to hold his own on both primal groudon and kyogre at once. As well as even take on those two again, Dialga, Palkia, Giratina, Kyurem and Hoopa Unbound. Granted, he was assisted by Latios and Latias, but he was shown to be able to knock back giratina and kyurem white. Who were both heavy hitters in their respected trios.