Envy's jaw tightens a little. He has an idea of what might work, but he can't bring himself to do it. That week he spent human--he doesn't dream, so he can't claim to have nightmares. It haunts him in its own way. "Most of us aren't just the stone. Sloth was like a chimera, as many animal parts as anything else, and Gluttony started as the False Gate of Truth. Lust, Greed, and Wrath all have human in them." Envy elides past that as fast as he can. No. Leaving aside the question of raw materials? Just no.