[Valerius]

Army of Gold and Weapons of Sharpness are E4. Weapons of Sharpness in particular is arguably too low. An E1 mage with earth boots and summon earthpower can just burn a gem to cast a powerful AOE 25 spell. That's the thing with these high end earth spells - they have a large/battlefield-wide AOE so you don't need many of them. That also means fatigue is not an issue the way it is when you want to spam a spell. Petrify has a high requirement and you would want to spam it but I'm not sure why it has to be easy for non-E nations to cast.

The problem with Tome of Gaia is ideally you want to keep the same forging paths as for the blood stone. If you do that you are giving nations access to an N booster they wouldn't otherwise have.