Class changing, are we unique?

[Jonnycbad]

Hmm...not really. BoTD (and such) are related to the relationship between you and Middy, not the soul crystal; it's not Estinien who uses Geirskogul, it's Nidhogg.

I don't remember there being mention of Midgardsrmr at all during DRG quests. Source? Also, BoTD abilities come from being the Azure Dragoon and drawing power from the Eye of Nidhogg. You don't need to be in actual possession of the Eye to gain its benefits. When Estinienhogg uses Geirskogul it's presumably because Estinien's body has the Eyes on it and can use the ability, because Nidhogg doesn't use it in Dragon form. Estinienhogg also uses Jump abilities which indicate he is tapping into Estinien's gifts but tainting them with his own aether, which is why his geirskoguls and jumps are purple/blacl.

Geirskogul is basically a technique whereby an Azure Dragoon taps into the aether of Nidhogg and releasing a bit of the Dravanian's aether as a blast from the tip of the lance and BoTD is tapping into the aether from the Eye of Nidhogg through the Soul Crystal as a conduit to enhance our abilities. Presumably, Wheeling Thrust and Fang&Claw require great strength and agility and the Dragoon requires the extra energy from a Dravanian to execute them, which is the lore reason as to why they are gated behind BoTD. No eye of nidhogg=no BoTD abilities. They explain in the story that what makes Azure Dragoons different from regular Dragoons is they can tap into Nidhogg's Eye no matter where its location is. That being said, BoTD/BL/Geirskoul all stem from summoning forth that power without being controlled by Nidhogg's rage.