Admittedly, it could be more balanced... but unique weapons, etc. tend to be in history, and tend to be badass stuff that everyone else would kill to use. Keep in mind, Erik's last blacksmithing teacher was Wayland Smith, aka the dude who made Gram according to Scion. That sword that killed Fafnir? Quite literally, in the Scion game, did 3x damage to Fafnir, and double damage to other dragons. Also sharp enough to cut an anvil in half.
Wayland smith, also known as Volund/Volsung, and other names, that is. Who was also notorious for making metal wings that would let him fly, after the local king chained him to the local forge and hamstrung one of his legs to keep him from running off.
So I'm leaving it, as it's the exact sort of magnificent bullshit his teacher would have made by sheer happenstance. Because when Wayland was genuinely able to make a pair of wings that would let him go to divine realms and back, just from the skill of smithing alone... you know that his student will occasionally achieve similar stuff. If having no clue how the hell he did it yet... also, keep in mind. ERIK STILL IS A GOD. He might be posing as a demigod to live with the rules of Gaia but his soul still contains that full divine might of legend 12.