"But the resources of a planet are limited—especially mana, which comes from the universe itself," Tyler pointed out. "If the planet was cut off from the larger cosmic flow of mana, then there are only so many possibilities."
He paused, organizing his thoughts. "Either the remaining mana on that planet has been used as a conduit to sustain the device, array, or runes ensuring its concealment and protection… or after millions of years, it has simply been consumed."
He glanced around the room before adding, "And as for lifeforms on that planet? If they once thrived, their numbers would have dwindled after millennia of captivity. Even if they somehow managed to absorb what little mana remained, their evolutionary path would have stagnated—completely cut off from the natural order of growth."