I've been reading posts when people scale Juubi to god tiers but after some research, this is far from the truth.
The Juubi which fought Hagoromo and Hamura isn't the same mindless Juubi which was used in the war. It was a mindless beast which spammed its attacks left and right but when a concentrated barrier was surrounding the Juubi, it couldn't deal damage to it at all.
When Obito absorbed the Juubi, he learned to use its power and thus, grew stronger than the Juubi. Yet, 1 Rinnegan Madara would beat the shit out of Juubito - and even the same Juudara, someone far stronger than Juubito, only reached Hagoromo's level when he absorbed the Shinjuu Tree and gained his 2nd Rinnegan. That's when god tiers truly start. Juubi is still far from it.
Furthermore, nowhere in the war arc has Juubi ever shown the feat to pull the moon, lol. This thing didn't even have the chakra control to break Hashirama's barrier and people believe it is pulling a Toneri feat? Toneri himself was Hamura level near the end of the movie with the Tenseigan. And even without the Tenseigan, Toneri is an Otsutsuki, just like Asura and Indra. So it's obvious where he stands.
About Mother Flame, no character scales to the ancient weapon so far, so even if this weapon can destroy planets, OP top tiers are far from this kind of power output as well.