A stargate. I'm assuming it will let the elves stage an invasion directly at the heart of the magus alliance with a fleet of ships. The probably have another set up in the elves territory
Like the name implies, I think it's a gate something like a teleportation device or spell but on a larger scale that can move Elf from their planets to this planet & destroy the alliance from within.
now hopefully emery doesnt share the replicator and uses for his own faction or himself when he goes back to earth.
It will come in handy to create spiritual plants for apocthery.