Storm is the most dangerous mutant of them all.
X of Swords Predictions.
From what I can see above, there are a few keywords, one of them being Storm having Elderly blood and Elderly God Powers, which puts her on the same level as Chthon but the benevolent side of the Elder Gods. Apocalypse seems to have been a hero for the first time when he banished Chthon in the alternative world.
Sword of Bone is an essential part of the whole story it is one of the four artefacts of creations, or corners of the universe and when it is gathered with the rest, it allows complete rewriting of the reality.
Storm seems to be the natural owner of the Bone Sword, through her bloodline, which makes me think that she is one of the Elder Gods or at least their spouse. She is capable of becoming one of the most powerful creatures in the entire universe, equal to One Above All, or at least a bit below his rank.
Storm will probably be the only one who can defeat Chthon, with the help of the Sorcerer Supreme, the only, ever, one (Ororo) who can banish him or obliterate him if she entirely takes on her Godhood and her Omega Level as a mutant. Something tells me that she will be using White Magic, or more precisely Order Magic. A very high class of Magic which even the Sorcerer Supreme will not be able to fully understand or cast, aka ending up with her being sturdier than almost everyone in the Marvel Universe, except the Universal Beings, like One Above All. Or the other Elder Gods.
Very high speculation, most likely not going to happen:
If the Sword remains in her possession and it is breaking down and implant into her, she will become the living embodiment of the four corners of the universe. This means that she will not just jump in space but also expand beyond Omega, beyond Odin himself, and her powers will reach equality, or at least full equality with the One Above All. However, this is most likely not going to happen, she will be way too powerful, and this means that she will end her participation in the most comics, which is not the aim for which Marvel is going.
What I believe will happen is her becoming one of the new Elder Gods, a Universal threat and since she is the balance, she will play on both sides good and evil, and X of Swords will start showing precisely that. Concentrating more on her evil side, since balance must remain, but then she will get back to the good side, but her actions will remain evident, probably making her fear, who is she, truly.