Rough Idea

Perhaps an upgrade to a philosopher's stone which allows one to input essentia and use it to replace blocks?

• Can be filled with essentia somehow, with chambers for each essence, cannot push essense back out
• Can replace areas of blocks (configurable?) (~5x5,7x7) at cost of their essense cost
• Needs to be recharged with materia? (maybe a GUI that can be access with a slot for each?)
• Dependant on blocks used to be replaced, fills self with materia

Maybe even a builder's wand type mode which just places?