Eminence of Blades was created by Stormwatch writer Paul Cornell and first appeared in Stormwatch #1.
Major Story Arcs
The Dark Side
In his first appearance, the Eminence of Blades travels under the orders of the Engineer to investigate the Moon which has seemingly become hostile to Earth. There he encounters the Scourge of Worlds, who wants to "make the world stronger through destruction". The Scourge digs into his mind and sees what seems to be his past, showing what seems to be the fact that Tanner has lived through many different eras in the Human History. It is also suggested that the Demon Knights were the first incarnation of Stormwatch. The Scourge also learns more about Stormwatch as a whole, before he attempts to use Tanner's body as a "host".
Tanner ends up resisting the Scourge of Worlds subconsciously, but he then offers the latter a partnership. Tanner proposes that the Scourge would give him its knowledge, without altering his persona in any manner, so that with that, he could resolve Stormwatch's leadership issues. He claims that this solution would be for the best because it would allow for both their objectives to be reached.
It is eventually revealed that Tanner has been entitled the Prince of Lies, which is proved by the fact that he eventually turns on the Scourge when the latter is attacked by the Engineer's data miner. Tanner knew that his partner would use the data miner and used the opportunity of having his mind connected to the Scourge to "do some rewiring" to make him vulnerable to the data miner. Tanner then becomes greedy and absorbs all of the Scourge's knowledge, at the unfortunate cost of destroying part of the Moon and sending the debris into Earth's atmosphere, one of which sets a monster loose in the middle of Colorado, with little civilization around it. Tanner is then seen absorbing the last of the information from the Scourge, and revealing his true nature to it, then turning on it and trying to kill it, describing the consequences as small, compared to what he had acquired. Angie and Jenny Quantum then appear and he leads them to believe that they have saved him from the Scourge, kissing Angie and then leaving as the Moon's caverns crumble.
Later, Tanner joins the rest of Stormwatch as they attack the monster, buying Jack Hawksmoor time to contact an ancient city. When the plan fails, he, along with the rest of Stormwatch, except for Midnighter and Apollo (and Projectionist, who is at the base), are absorbed into the monster. The monster gains their powers and continues it's rampage. Midnighter, aided by the late arrival of Apollo and support from the Projectionist saves the absorbed members of Stormwatch. Then Tanner worked together with the Engineer and Apollo, fighting the monster, while the rest of the team searched the city to find a special alchemist power stone, that was powered by Jenny to turn the creature into glass.
He is later seen with Angie, then when the team comes back to their base, they are confronted with a mysterious individual who claims to aim to kill Adam One because his failure as a leader of Stormwatch. Following this encounter, Tanner decides to create a diversion, collect some data hidden in the Stormwatch base and leave the team. Midnighter later confronts him about his betrayal and the two engage in combat, neither gaining the upper hand. Eventually the Projectionist interrupts them and Harry uses this as an opportunity to launch himself into Hyperspace with her as his hostage and blowing an alien horn with a previously planted device, nearly destroying the Eye, Stormwatch's base of operations.
Since escaping from The Eye, he set up a base in Antarctica. He is accompanied by the Projectionist, who seems at first to be more willing than one might expect, even romantically involved, though this is likely just to ensure he does not kill her. Harry began raiding caches of supplies hidden by Stormwatch across the globe over the years, at times using them as diversions to keep them off his trail, all the while putting together an elaborate plan to take down Stormwatch from the inside.
His plan involves tricking small time criminal The Fox into acting as a sort of dimensional portal, which Harry uses to acquire technology needed to disguise himself as one of the Shadow Lords. Using his exceptional powers of persuasion he is able to convince them he is a long missing Shadow Lord, and proceeds to announce that he has foreseen a new direction for Stormwatch.
Harry next appears on the Eye of the Storm still disguised as a Shadow Lord, and tells Stormwatch that they are to take a more proactive approach to the superbeings on Earth, and tells them to kill Superman, Batman, and Green Lantern, saying they are "a threat" presumably in the hopes that Stormwatch will kill themselves in the attempt, or at least weaken them. The Projectionist also makes a return, and it is revealed that Harry has somehow implanted a false memory in her mind of him dying in an explosion, and plotting against Stormwatch with Midnighter. Midnighter sees through Harry's disguise, and tells the others that Harry is trying to trick them, but to no avail. Harry tells them to arrest Midnighter, who abducts Projectionist and heads out a Door into Antarctica in an effort to uncover evidence that Harry is the 'Shadow Lord'. While tracking Midnighter, he kills several researchers, which he uses to frame Midnighter for murder, and convince Stormwatch that he needs to be killed.
It has been alluded to that Harry Tanner has a romantic relationship with the Engineer. The two shared a moment together when Angie came to save Harry from the crumbling cave system and later were together when they fought off the monster sent by the Scourge of Worlds.
Tanner's powers and their effects have yet to be fully demonstrated, but it is known that he can create some sort of energy and imbue it into his swords. The specific effect of this energy is unclear, although it may alter the physical characteristics in his swords. He is the self described greatest sword fighter in history.
Harry Tanner has been referred to as the Prince of Lies due to his skill in the art of lying and deceit. It is implied that he has some sort of metahuman power related to deception. This "deception power" aids him as a swordsman, making his feints very effective, in addition to adding to his prowess as a tactician.
It has been hinted that Tanner is an individual with a long lifespan and as such has significant combat experience.
He has shown to be able to fight toe-to-toe with the likes of Midnighter. Furthermore, he's also shown the ability to actually create his swords from nothing, during the fight he had with Midnighter.
It is possible that Harry possesses some form of telepathy, which he uses to convince others to believe his lies, no matter how outlandish, and implant false memories. However, some people, namely Midnighter, seem resistant.