It makes sense since the phoenix power needs a counterweight. But why you take wyrmkiller away again, it cannot disappear on it's own despite being intelligent it's persona was never a mage. It's disappearing and reappearing is my own doing using the bond between us which is not easily broken. Also the spirits know nothing about it as this isn't their original world as well ascertain events. They originate from the elemental chaos, which they are responsible for it's current state as mentioned in shade's description.
The pinnacle spirits DO know about it, though, because Salamander has been persistently trying to separate you from the weapon. Since you were siding with Salamander, the reasonable countermeasure was to remove Wyrmkiller as the two are opposed.
I caught a glimpse of a different post the other day, but didn't have time to read the whole of it. I know you're having a crisis of character definition, though, so here are the options available to you.
+Dragonkin, -Phoenix
If you're upset about Granberia losing her dragonkin characteristics, the best course of action would be to seek out Cecette. She has the prowess (with Lycaon magic) to revert you to your former state.
However, she's not going to do this for free. This reopens the mind control plot, and also adds a dangerous complication: Cecette is going to want the phoenix pearl.
Since you (Granberia) were able to take a pearl and reconfigure it to your own personality, Cecette will see it as an avenue to regain her draconic power (It's even worse, though, because it's charged with phoenix energy).
So this option would remove your phoenix traits and restore your dragonkin status, but with the complication of giving Cecette leverage over you (and possibly the entire group).
+Wyrmkiller, -Salamander
Salamander does not trust the Wyrmkiller, and with good reason. She doesn't know the entirety of its dark power (SHADE does) but she knows it is evil and she knows that it is manipulating you (Granberia).
Therefore, if you continue to take up the sword, Salamander will break her pact with you, as shunning is the only way she can hope to help you. She doesn't want to watch you destroy yourself.
Wyrmkiller vanished because of Math magic (again). Who is moving the sword, though, and THEIR motivation, is something I am aware of which will not be revealed to you at this time.
I can bend my plans and return the Wyrmkiller to you, but expect your contract with Salamander to break if you reclaim it.
+Vendetta
I know it seems like D'Arsonius is gone and you've lost your primary motivation. But there's still a free pearl floating around in probability; he's still OUT there. Becoming a phoenix has not broken this plot.
When and if you confront him in his final incarnation is up to you.
You are free to take any of this options, any combination of the three, or none at all.
Follow the development which you feel is most appropriate for your character; I am prepared to handle any of these situations. I only made you a phoenix because I thought it was an interesting twist in a positive sense (like when Cecil became a Paladin in FF-IV) and I thought you would enjoy it. Again, do what you feel is best for your character.
(Read 10-26-15)
-C
