Before Constantine There Was...John Sinclair!

 

My brother, Mike, says this is all very John Constantine in look and, well, yes and as he points out goes well back to the 1970s.

All my John Sinclair stuff is on one disc somewhere but there is a very good Wikipedia entry here: https://en.wikipedia.org/wiki/John_Sinclair_%28German_fiction%29

I will quote this part of the entry as it explains a great deal -I'm sure Subzero knows more than I do about this!  In fact...yes, he does mention the series: http://talesfromthekryptonian.blogspot.co.uk/2015/01/more-recycled-covers-from-gespenster.html

John Sinclair is the name as well as the protagonist of a popular German horror detective fiction series . Sinclair, a Scotland Yard chief inspector, battles all kinds of undead and demonic creatures. The series appears weekly and has been running since 1973.

The full title is Geisterjäger John Sinclair, ghosthunter John Sinclair. While falling into the category of 'pulp fiction', the ongoing series is yet remarkable for the relatively wide range of its vocabulary and the inventiveness of its plots.
 
Almost all John Sinclair stories in the series have been written exclusively by Helmut Rellergerd under the nom-de-plume of Jason Dark. Only a few of the earliest stories have been written by other authors. As of late, creation of new stories is divided among Rellergard and several new authors, each of them writing separate full episodes; the new writers are attributed for their respective stories.

Over the decades the Spanish painter Vicenç Badalona Ballestar has created numerous paintings and illustrations for the bestselling series.

Rellergerd narrates the stories in first person from Sinclair's point of view whenever he is involved. At all other times a neutral narrator style is used. In some stories Sinclair does not appear and one of his friends takes the leading part.

 John Sinclair is of Scottish descent and the reborn soul of both King Solomon and Knight Templar Hector de Valois. He is a direct descendant of Henry I Sinclair, Earl of Orkney. John Sinclair is described as 1.90m tall and blond in his middle thirties. Like most characters he does not age during the course of the series. He is called the Son of the Light and wields an extremely blessed cross as well as a Beretta handgun with silver bullets. He has acquired and lost other weapons during the series. Sinclair is a bachelor, never really having a girlfriend during the series. The one time he did fall in love, his fiance turned out to be a trap set by his enemies. 

Suko is Sinclair's colleague as a Scotland Yard inspector. He is a Chinese proficient in martial arts. As an additional weapon, he carries a whip made from the skin of demon which instantly kills all undead or demonic beings except the strongest. He has no first name, being called just Suko or Inspector Suko. Suko was brought up in a Shaolin temple somewhere in China where he learned his martial arts and discipline. Originally the driver of a powerful Chinese patron in London, he joined Sinclair after his patron and the latter's sole daughter were killed by a dragon-worshipping cult. 

Sir James Powell is the direct superior of Sinclair and Suko. He rarely gets involved directly into the action, mostly giving information and valuable support and cover from his office. Sir James can arrange a lot of things due to his status in society and his connections. He has complete confidence in his team. 

Glenda Perkins is the office secretary, especially famous for her coffee. She has served as one of several love-interests of Sinclair. During 2006 she was injected with a nano-tech serum enabling her to teleport. At first she could not control her teleport ability, but recently she has begun to master it quite well and is even capable of taking one or two persons with her. 

Shao is Suko's permanent girlfriend. She is Japanese and the reincarnation of the Japanese Goddess Amaterasu, also known as the Phantom with the Crossbow. 

Bill Conolly is a close personal friend of Sinclair's. They have studied together and been friends ever since. Bill is a freelance investigative reporter and sometimes gets involved in Sinclair's cases. He married early in the series. 

Sheila Conolly, née Sheila Hopkins, is the wife of Bill Conolly. Her father was a rich industrialist killed by the demon Sakurro. 

Johnny Conolly is the only child of Sheila and Bill Conolly, and John Sinclair's godson. He is the only character to age during the series, growing up into a good-looking young man currently attending the University of London. Johnny Conolly occasionally gets involved in Sinclair's cases, much to the dismay of his mother. 

Jane Collins is a former witch who switched sides during the course of the series. When an agent of Asmodis cut out her heart, she had to have an artificial heart. Collins works as a successful private detective, only occasionally appearing in the series. After the death of Lady Sarah Goodwin, she inherited her Mayfair home and other possessions. 

Lady Sarah Goldwyn, also called the Horror-Grandma, was a collector of horror books and films as well as antiquarian volumes on magic and the supernatural, making her an expert in the field. She took Jane Collins into her Mayfair home, bequeathing it to her when she was killed by the monster vampires of the Black Death.

Villains, etc. are discussed in the Wiki entry.

The Germans, of course, love their royalty stories and upper-crust Brits (seriously, 1970s-1990s mags  were so full of stories and photos of ANY Royal family and it might explain all the Sirs and Ladies in the series!

There are kindle book editions on Amazon if you read German....or you could try to find the books but so far I've had mostly negative dealings with German sellers online!