OP magazine is not canon
You know that 400 years old is speculation right? We don't know exactly.
Plus we don't know about the Nidhogg DF, when it became a national treasure.
And it seems you are assuming a giant was the owner of it. It could have be a human, a squirrel, an ant...
Plus we don't know about the Nidhogg DF, when it became a national treasure.
And it seems you are assuming a giant was the owner of it. It could have be a human, a squirrel, an ant...
Ignoring that completely, Onimaru confirmed Ryuma lived centuries ago.
His grave is in Ringo, where he was born after the walls went up 800 years ago.