What's your wrath? If you only got to bring one SC unit into this universe, a drone would be the most logical choice. It's the only thing which can logically create all the others. Probes don't build, they warp things from Aiur (which doesn't actually exist (god knows why that takes minerals/vespane)). SCV's might or might not work. I assume that raw materials like metals could be used in place of the minerals/vespane (again, only the SC gods know why metal buildings require such), but such a structure would be difficult to hide/tracked and confiscated by the government rather easily. So, on a planet-sized map, what unit do you have that could find/destroy me before I get established?