She wants you to become a hero

Althena smiled at you with an expression that looked to hide unimaginable sadness. "It might be better if I showed you." She said before her slender fingers wrapped around your cock while her other hand grabbed your head, touching her thumb to your forehead.

You saw horrors. You saw tentacles slithering down from bleeding tears in the fabric of reality. You saw once peaceful streets become infested with gibbering monsters that hunted down, consumed, and mutated innocent people into gibbering horrors. The scene changes. You saw flying saucers deposit disgusting aliens that attack New York, London, Tokyo, Shanghai, Singapore, Cairo, and countless other cities. You see men, women, and children bound in chains and packed into alien cargo ships to be sold as pets and food animals on the galactic market.

Then you saw warriors armored in arcane powers soaring through the void on wings of light smashing these horrors with awesome cosmic powers. These mystic star knights are cheered as heroes by the masses as they are feted and celebrated. "John, your world, every world, is under constant threat by countless beings that want to enslave or exterminate the humanoid races. The only thing that stands between innocent people and the horrors that want to consume them are my Star Sentries. An elite **** of champions."

"But. I am no hero. You need like, Delta **** or MI-6." You said.
"It has to be you." Althena insisted. "and if you refuse, then there will be nothing standing between your world and the Squillachi invasion fleet heading towards Earth as we speak."
"WHAT!?!" You got to your feet. You felt your heart pounding in your chest at this new and shocking news. "Your telling me, that if I say no, then..."
"Your civilization will be destroyed, and all eight billion people on this planet will be consumed." Althena said flatly. "No pressure."

What else can you say to that other than. "Okay. You got yourself a Star Sentry."