Flying Horror Warhammer fantasy battle 8th edition Vampire Counts Vampiric Power
This Vampiric Power does exactly what it says on the label (well at least partially) and grants the Vampire with it the ability to fly with the Flying special rule. Sadly it makes them no more of a horror then they were before for that you would need the Supernatural Horror Vampiric Power.
As a cheaper Vampiric Power this is available to Vampire Lords, Strigoi Ghoul Kings and Vampire heroes however unlike 7th edition in 8th edition this Vampiric Power stipulates you must be on foot to have it.
Pros and cons
Pros are it is available to any Vampire on foot and you can use it to suddenly surprise your opponent with a unexpected move or charge. This charge could often be a unit such as a war machine that they thought was "safe". Its also a good way to make your Strigoi Ghoul King that bit faster and more flexible.
Cons are with the flying Hellsteed available to all Vampires as an equipment option that does not eat into your Vampiric Power points allowance it can be a better choice as it also gives you another attack and +1 armour save as well as changing your troop type to cavalry (saving you from the Skaven's Dreaded 13th spell).
With the same points cost each can be a viable option depending on your oppenents army and your intentions for the flying vampire.