Maybe genbuckets like on the Archon are an option. You can select what block you want to place horizontally (as a wall). Every block differs in price. The downside of this is that is makes you lazy but it spares you a lot of time. Just an idea Edit: Ofcourse obsidian should be destroyable so add a durability to them. Maybe also flying in your own faction territory so its easier to make a base etc but this is also just an idea (When there are enemies around you should not be able to fly)..