Vamphyri!

The heart of this star-spanning story is the chilling tale of mankind's unending battle against black-hearted, shape-shifting, blood-thirsty, alien vampires - and of one man's battle in particular: Harry Keogh the Necroscope!
Harry is the man who can talk to the dead, the man for whom every grave willingly gives up its secrets. In the original Necroscope trilogy Harry discovers that his powers are even greater than he thought - he can also travel effortlessly through time and space. Thus Harry Keogh becomes the one man able to attempt to eradicate the vampire evil at its source.
Harry's enemies are many - the vampires and their gruesome thralls and genetically altered servants, the Russian ESPionage service, and others. He's even been killed once already, forced out of his body and into that of Alec Kyle, head of Britain's E-Branch. Luckily he has a few allies - E-Branch, an organization of psychically gifted spies...and the teeming dead, for whom Harry is a ray of light in an otherwise dark existence. There are millions of dead people who would do anything for Harry Keogh.