I am a dragon slayer and killed Alduin

Alduin (also called the World Eater, the Nordic God of Destruction, and A.svgL.svgD.svgU.svgI.svgN.svg in Dragon language), is a dragon whose return was a result of an Elder Scroll. He was first removed from Tamriel through the last resort of the ancient Nord heroes who used an Elder Scroll to force Alduin to become lost in time and hopefully never return. Instead, he was sent forward to the Fourth Era, to the timeline of events in The Elder Scrolls V: Skyrim, and the Dragonborn's Story. Alduin's triumph would ensure Nirn's destruction.
A Dragonborn (transliterated from D.svgO.svgV.svgAh.svgK.svgIi.svgN.svg to Dovahkiin in the Dragon language) is a rare individual who has been born with the blood and soul of a Dragon, but the body of a mortal, and can naturally learn and speak their ancient and powerful tongue.

Dragonborn scarcely exist, and it is rare for more than one to appear within an era. They can belong to any race or gender, since the Dragon blood (transliterated from D.svgO.svgV.svgAh.svgS.svgO.svgS.svg to Dovah Sos) is a "gift" bestowed to certain mortals favored by the gods. Able to use "Dragon Shouts" (transliterated from T.svgH.svgU.svgU.svgM.svg to Thu'um), the Dragonborn can consume a slain Dragon's soul and absorb its knowledge, allowing them to learn words of power quickly and making them more effective in battle against Dov than other men.[1] It is said that the Blades have always guided and served the Dragonborn, whom they consider "The ultimate Dragon slayer".[2]

The "Prophecy of the Dragonborn", generally attributed to the Elder Scrolls (and some times to the ancient Akaviri) tells that, at the end of time, in the wake of the World-Eater, the wheel will turn upon the "Last Dragonborn"