Lyon, Garm, and Gleipnir

[Paper Jam]

It seems odd (and Ephraim called attention to the oddity) that Lyon would leave Grado's Sacred Twin relics in the shrine after he had destroyed Grado's Sacred Stone. Knoll implied that Lyon wanted Ephraim to find them: "I want you to have them. And maybe... Maybe someone else wanted you to have them as well."

Which makes some sense in light of the next few chapters of Ephraim's route, which reveal that Lyon was struggling with the Demon King for control over his body and was at least partially successful. At the very least, Lyon had enough sanity left to want Ephraim to stop him from resurrecting the Demon King.

However, in Eirika's route, Lyon has considerably less success in resisting the Demon King's influence, and thus the idea that he would leave Grado's Sacred Twins for Ephraim to find (as he does in Eirika's route too) makes considerably less sense to me.

[KMT4ever]

Don't forget that on Eirika's route you don't actually see Lyon until chapter 17, although I may be wrong on that. It's entirely possible that he lost his sanity faster, but still had enough when the capital fell to leave Grado's Sacred Twins intact.

[General Horace]

In Chapter 14 Eirika route, when Caellach kills Ismaire, Lyon is still supressing the Demon King (to an extent) as he objects to killing her, and Chapter 14 Eirika definately happens later than Chapter 14 Ephraim when he gets Grado's weapons (since Grado is a fair distance away from Jehenna and you'd have to give Ephraim time to arrive there, and even on Ephraim's route, Eirika and co are already present from turn 1)

So I think it makes sense.