Two (related) things:
Is it possible for Demonbane to be in storage in Yggdrasil, and only be teleported to Kuzaku when it's direly needed? Just to play up early-game Demonbane being a sparingly-used asset of the Hadou Group, and firmly establishes when the correct time to use it is.
Would I need to call in a Lemuria Impact, once Demonbane is active? This is also something Demonbane needed to do in the games, requiring the Nacal Code to be transmitted from HQ for it utilize its most powerful attack. Another limiter the UMMA (and by proxy, VVAR) could place on the Deus Machina.