Seek out new life and civilizations. Kill them for their mana. Aliens are blown away by science.
Daniel Thrush is the only known human with the ability to learn the magic which runs the various empires of the universe. Earth is in the crosshairs of the Tellask Empire, a race that discovered magic millennia before humanity even mastered fire. All known aliens focus on the arcane. Upon learning of magic, their technological progress all but halted as great voidships spread their colonies across the galaxy. For all of Earth's military might, their only hope is to incorporate the alien's magic into technology, to use the enemy's own tools to fight them. The government is dead-set on transforming magic into a standard-issue weapon. That means finding monsters and harvesting their mana, usually after sticking them with a sword. Despite his better judgement, and the world on his shoulders, Daniel leaves Earth behind to bring them back a future.