He was raised by the ottomans .. Later he became their worst enemy .. N was supported by the Christian empires... He wasn't just some random janissary.
He was a royal hostage to Istanbul for much of his childhood (like his brother), trained and raised like the son of any high ranking Turk noble. He probably knew Mehmed from childhood.
Unlike his brother Radu he never embraced the Turkish culture and when he ascended to the Wallachian throne became the archenemy of the Ottoman empire, unsupported by other Christian countries . (albeit he was less successful than his contemporary, Stephen). He was a very, very cruel man, but it's debatable if he was the monster portrayed by the German and Hungarian chronicles (Russian and Wallachian chronicles portray him in a much better light)
The irony is that Sthephen was a much more succesfull ruler than Vlad(wich was his contemporary-Sthephen in Moldova,Vlad in Wallachia) with many more battles won, but outside Romania he's much less known .
No vampires