I am Stormblade who helped Ulfric liberating Skyrim;
I am Archmage who saved College of Winterhold;
I am Nightangale and Guild Master who restore the influence of Thief Guild across Skyrim;
I am Listener who assassinated Emperor;

Valkis: I do not know this outsider...

Valkis, you are so ignorant
If I defeat Alduin, will he recognize me?

Probably not. He doesn't have a subscription to the Black Horse Courier it seems, otherwise he should know you pretty much do everything in Skyrim.