Simon R. Green's Secret Histories is about Shaman Bond, aka Edwin "Eddie" Drood, black sheep of an ancient, superpowerful family (the Droods) that protects humanity from its nightmares. The books are a take-off of Ian Fleming's James Bond books with a supernatural element to them.
Sunwrack — For putting out the stars one at a time.
Juggernaut Jumpsuit — Possibly makes the wearer invincible
The Time Hammer — For changing the past through brute force.
Winter's Sorrow — Size of a paperweight. Break it and you unleash the Fimbulwinter: an eternal winter that covers the world.
Dissector — the ultimate scalpel created by Baron Von Frankenstein. It can cut through any thing, neat as you like.
Dominator — A laurel wreath made from silver. The user's thoughts and wishes becomes other peoples thoughts and wishes.
The Merlin Glass — can be used to teleport and contact any Drood from the past and future.
Armor Is Useless: Averted except in three instances in the first book, when the strange matter arrow pierced the golden armor, when Eddie figures out how to merge it with the armor of his opponent near the end, and when dealing with Torc Cutter. Other than those times, the golden torc is indestructible as long as it is on.
Walker: "I could handle Good Time Georgie if I was unconscious." He smiled easily into Georgie's reddening face, completely unmoved by the man's size or presence or anger. "Are you sure you want to do this? Are you really sure I don't have my Voice anymore? Would I be here in Strangefellows, without my Voice to protect me? Perhaps you've forgotten all the terrible things I've done to you down the years. Or made you do to yourself. You're just a cheap thug, Georgie, whereas I... am Walker. Now go away and stop bothering me. Or I will tell you to do something deeply amusing and so extreme that people will still be laughing about it thirty years from now."
Beethoven Was an Alien Spy: Early on, Eddie mentions that many of the conspiracy theories in pop culture are true. Mr. Stab began his career and immortality as Jack the Ripper. A family really does (or did) control the world.
In Daemons Are Forever the Droods are revealed to be the ancestors of Giles Deathstalker.
Janissary Jane (in both Man with the Golden Torc and Daemons are Forever) also appears in the Nightside series.
Walker from Nightside is a character in The Spy who Haunted Me and then reappears after his death to question the now dead Eddie for his new bosses in For Heaven's Eyes Only.
In From Hell With Love Methuselah was in the Nightside during the events of Agents of Light and Darkness and steals an angel's hand, then makes it into a hand of glory.
Merlin Satanspawn gave the family the glass which bears his name in payment of a favor.
Dead Boy from the Nightside and J.D. Chance of the Ghost Finders attend the Casino Infernale Summit meeting and turn up at the end for the final fight. The Little Lord, a minor character from the Haven stories, shows up as one of the gamblers in the Casino itself.
Chekhov's Gun: The James Bond like devices Eddie gets. Subverted in The Spy who Haunted Me (2009) since Eddie never uses the items his uncle gives him to his uncle's extreme frustration. However in From Hell With Love (2010) he uses the items he didn't use in the last book.
The arrow that makes it through the golden torc comes back in full force by the end of the first book.
Fantasy Kitchen Sink: Psychics, aliens, spies, elves, gargoyles, werewolves, ghosts, zombies, angels, demons, Frankenstein's creations, witches, interdimensional mercenaries, Lovecraftian monstrosities, satanists, superscience of various stripes and a few superheroes to boot.
Fate Drives Us Together: Subverted an Hell to get an agent cozy with the Droods. However, Roger actually does fall in love with Harry.
Instant Armor: The Droods' chief asset in their countless world-saving battles is the magical golden (or silver, in a couple of books) flexible armor that retracts into their torcs when it's not needed.
Light Is Not Good: The golden armor is powered by the dead soul of each Drood's twin, sacrificed shortly after birth.
Jack the Ripper: Mr. Stab performed several gruesome human sacrifices in Victorian Whitechapel in order to obtain immortality. It worked, but this form of immortality had consequences for which he was not prepared.
Shapeshifter Showdown: At Casino Infernale, this trope is offered as one of the Medium Games. Played with when Shaman competes, as he mostly battles his opponent in his human form, rather than transforming into powerful shapes.
Lampshaded in Daemons: "So," I said. "I am left with just a few days to stop the bad guys from destroying the world and save the family from itself. If I hadn't already done this once before, I might be seriously worried."
What Happened to the Mouse?: When last seen in The Spy Who Haunted Me, Coffin Jobe had succumbed to his necrolepsy and died at the Independent Agent's secret lair. It's never mentioned whether he revived in time to leave before Eddie and Walker finished looting the place and blew it up. Even Jobe's cameo appearance in For Heaven's Eyes Only doesn't resolve the issue, as Eddie's near-death experiences are an enigma in themselves.
Who Wants to Live Forever?: Happens to Methuselah. He wants to leave earth because he's done and seen everything. He also wants break into heaven to enjoy its splendor.
Woobie, Destroyer of Worlds: Doctor Delirium, a villain who threatens to unleash diseases unless he is paid ransom in rare postage stamps — once a collector, always a collector. He sends his goons to steal the Apocalypse Door in order to make the world take him seriously.