Im sorry for losing my temper earlier. But I would very well like to clear all this up and put an end to all this.
So just to clarify, when Rhea was hit with the Javelins of Light, she was already in a very weak state. Only afterwards in Silver Snow, did she go Beserk. She was not in her true beserk form, nor was she at full health when she tanked them. Despite this, she could still tank point blank Javelins of Light. This means that a full power immaculate one from Crimson Flower (That isn't beserk) should be far more powerful than the one that tanked the javelins of light. You could also argue that the Beserk Immaculate one is actually more of a glass canon due to being near death prior to the transformation.
The crest stones should be at least half the strength of the lowball estimate of the Javelins of Light. One of the things that support this is the fact that resseructed Nemesis with the Dark Creator Sword (Which was powered by 2 ordinary crest stones) was able to fight toe to toe with Sothis-Fused Byleth, who had the Sublime Sword of the Creator. (Which was powered by the Crest stone of flames).
Now, we are not saying that Edelgard, or any of the other lords are more powerful than Byleth, since thats clearly not the case. However, they are still comparable in strength. Yes, Aymr is weaker than the Sublime Sword of the Creator. Despite this, we can clearly see Byleth and Edelgard fighting on multiple occasions. (Once at the monastery right after the timeskip in silver snow, arguably at gronder field, and at the imperial palace.) Even with a weaker weapon, Edelgard has shown to be somewhat comparable to Byleth.
Pre-Timeskip Edelgard fighting a Demonic Beast all on her one is pretty uncontroversial, as she does have Dual Crests, one of which is the strongest crest in the game. Not only that, she should be on par, if not superior to the likes of Claude and Dimitri who can
effortlessly one shot several Imperial Soldiers. Of course, I'm not saying these soldiers are as powerful as a crest stone, but still strengthens my argument that its not controversial, nor an outlier for Edelgard to be able to do that.
I mean we can even see this in the opening cutscene of the game, where Seiros is able to fight and kill Nemesis. For context, Seiros had the Sword of Seiros, and Nemesis had the Sublime Sword of the Creator. Sacred weapons are implied to be weaker than the Heroes Relics, but are still comparable in strength, as implied by Linhardt
here. The weapon you are using does matter, but not as much as the person behind it. I mean we can see Kirby, who with a literal baseball bat send a meteor flying thousands of light years away in seconds.
Edelgard definitely pulled her weight in the fight against the Immaculate one, as we can clearly see in the final cutscene of Silver Snow, in which the two are fighting against the Immaculate one. They are the ones that land the final blow as well.
As for cutting the mountain in half, its stated by Claude
here and
here. On the second link, Claude implies that even a regular relic could do the same. Claude is a reliable source for this, as he does a lot of digging around wanting to find the truth about things. We can see this when he managed to snatch a picture of the immaculate one before Seteth confiscated it.
I hope this clears up any remaining questions you have
