The Great Slave King, written by TalonMach5, opens with Andrew King — a regular guy — somehow ending up in Equestria. Captured by diamond dogs and forced to work as a slave, King eventually escapes after many years in captivity, but loses his friend and adopted daughter in the process. On the verge of dying of dehydration, he unknowingly stumbles across the Well of Eternity, ascending to godhood and setting in motion a chain of events that will permanently change the world.Now styling himself as 'The Slave King', the story from here follows his rule as Lord of the Earth as he attempts to gain revenge over those who have wronged him and outmaneuver his fellow deities.The second story in the series, The Marriage of the Slave King is set several hundred years later, shortly before the Slave King's 500th anniversary celebration, and revolves around several plots against him.Currently the author has stating plans for two more stories, and the series also has its own sidestory collection, presented in-universe by Trixie.
Tropes found throughout the series:
Agony Beam: The Slave King can use the magical brand on his slaves and servants to this effect and often uses it as a torture method to those that have displeased him. As a general rule, he always gives his newest servant a small taste of what awaits them should they ever betray or fail him.
The Slave King can also grant his servants power over a specific person's mark for this very purpose.
Scourge, though he loses his corporeal body and sacrifices his ability to return to the afterlife in the process.
The Slave King eventually manages to bring Little Bleu back after many unsuccessful attempts.
Battle Trophy: Both Darkpaw's pelt and skull are taken by the Slave King. He's almost never seen without wearing the former, and displays the latter above his throne.
Beat Still, My Heart: The Slave King's discarded heart in the Well of Eternity. While not strictly a Soul Jar variant, it is implied that it would need to be destroyed before the Slave King could be killed. It also means the Slave King cannot survive being stripped of his divinity.
Berserk Button: Almost anything to do with his dead daughter pushes this for the Slave King, to the point that he declares enmity towards all changlings because their queen attempted to feed off him by impersonating her. He also threatens to kill Bixie should she ever use his daughter's form again.
Arch Duke Fifi le Yipyap also secretly fears the Slave King's wrath should any of the liberties he took with her come to light.
Brilliant, but Lazy: Jormungandr is extremely crafty and intelligent, but is quite laid back and relaxed, to the point of falling asleep during moots and being more concerned over the lack of catering than one of his fellow deities lying dead on the floor.
Chick Magnet: The Slave King, despite showing a complete lack of romantic inclination towards any of the pantheon has nevertheless managed to attract the interest of many of its female members. While some such as Celestia are intrigued by him, for most however it's simply the novelty or the promise of sharing some of his power.
Performing the Renewal of Earth ceremony leaves whoever holds the position of Lord of the Earth in a rather amorous state.
Lady Suzaku's magic invokes this. Shaw tries to use this to his advantage as part of a quest when she grants him a feather.
The Slave King ends up inducing this in others at the anniversary of his 500th inauguration. He quickly realises something is amiss when even Nightmare starts acting extremely affectionately towards him.
The Slave King magically spikes the wine at his inauguration ceremony to invoke this with Lady Suzaku's help, to distract the rest of the pantheon from his Fee Fi Faux Pas.
Every God Has Lots of Sex: The pantheon during the first age, to the point where most of the gods have paired up at some time or another, which resulted in most of the species that now populate Equestria. This ends up making the newcomer Slave King quite attractive to many of the female gods, simply for the novelty factor.
Arch Duke Fifi le Yipyap is condemned to life until he has suffered enough to have "paid his debts in full".
The fate of those unable to enter the Summerlands.
Full Name Basis: Unlike the rest of the pantheon, the Slave King almost always addresses them by their name and title, something which confuses them. Eventually he explains that he learned this behavior during his time as a slave.
Glowing Eyes: Assuming the position of Lord of the Earth grants the Slave King glowing ethereal green eyes, later revealed to be due to him lacking any "magical organs" to deal with the surplus of magical energy he possesses.
The Greatest Story Never Told: Discord ended up saving Equestria from Tiroc long before The Great Slave King, but the mortal races are unaware of this.
Luna becomes increasingly jealous of the devotion and admiration given to her sister Celestia. Further, Luna also shows signs of becoming extremely possessive of the Slave King, to the point where any interest in him from other members of the pantheon, real or perceived, is met with this.
Lady Zephyr, having already fallen in love with the Slave King and still hoping to resume their previous relationship, similarly shows great jealousy whenever anyone else shows interest in him.
Complicating things further still, Lord Cerynitis is jealous of the idea of Luna showing any interest in the Slave King. This ultimately causes him to treat her cruelly, driving her away from him and towards the Slave King.
Nightmare tends to get extremely jealous of anyone else who shows affection towards her master.
Half-Human Hybrid: Several varieties, though only half-diamond dogs, half-griffons, half-phoenixes, and half-dragons have been mentioned thus far. The existence of the latter is something of a mystery in-universe given that the Slave King and Lord Ouroboros are male, and is of great embarrassment to them both.
Happily Adopted: While it's arguable how happy she is during her time as a slave, it's made very clear that Little Bleu deeply loves her adopted father.
Healing Factor: Divine beings possess this and can recover from most physical wounds very quickly.
Triton and his knights tend to suffer from this. Even when he is well aware he is being exploited in this way, Triton still refuses to compromise his honour, and carries on with an agreed deal.
Dragons consider honour to be paramount, and have almost no tolerance for betrayal and deceit.
Hypocrite: The Slave King, despite having experienced the horrors of slavery firsthand, has little problem with it when he takes over as Lord of the Earth. Though it should be noted that he does make many reforms to ensure better treatment of slaves.
The Ageless: Divine beings, though they are also fairly difficult to kill in their own right.
Complete Immortality: Those empowered by the Slave King take on this while under his protection, but this can be lost if the Slave King is weakened, or they step too far outside his domain. This also isn't always a goodthing.
Between Scourge and Second when they are discussing Celestia's supposed plot against the Slave King.
Infinity+1 Sword: The Vendetta, a weapon crafted by the Slave King which is powerful enough to harm gods. Simply creating it in the first place nearly killed the Slave King and almost cracked the world.
Nightmare. Scourge. Nidhogg. Indeed, most of those empowered by the Slave King tend to take on fairly intimidating names.
Tiroc the Destroyer
Noodle Incident: The creation of human-dragon hybrids in-universe, something which the Slave King and Ouroboros refuse to elaborate on.
According to Word Of God, the Slave King and Ouroboros accidentally merged their divinity while fighting a battle, something both find immensely embarrassing. Ouroboros only agreed to spare them after the Slave King offered him a favour.
Pet the Dog: The Slave King, despite generally being cruel and uncaring does show elements of this from time to time. Perhaps the most notable example is when he admits to his daughter Melody after she places herself in a dangerous situation that he would be quite distressed if she were killed, and to be more careful in future.
He also does this literally on very rare occasions, though they aren't always an actual example of this trope.
When Lady Suzaku presents him with a gift at his 500th inauguration ceremony, he's implied to be deeply touched at how much the gift cost her, and he immediately orders his daughters to go and comfort her when he declines her affections.
Darkpaw attacks the newly ascended Andrew King, violating the laws of creation right after being explicitly warned of the consequences. After being stripped of his divinity as punishment, King gives him one last chance to yield, which he refuses. Then he gets his neck snapped.
Sombra. Right after the Slave King warns him of the dire consequences should he maltreat the crystal ponies, he immediately starts abusing his authority the moment he gets there.
Undying Loyalty: Scourge to the Slave King. Quite literally, as Scourge under most circumstances cannot die, and later his loyalty to his master allows him to return from the dead to the Slave King's side.
You Have Failed Me: The Slave King and his underlings tend to dispose of minions who screw up especially badly.
Terrorantula to Sir Stouthorn in the Marelantis Coliseum
Terrorantula: I shall feed upon your carcass, and decorate my lair with your remains.
Sir Stouthorn to the Slave King when confronted for his refusal to surrender the Vendetta
Sir Stouthorn: At Jormungandrís Way I stood up to Scourge the doomhound without flinching. At the Marelantis Coliseum I battled Terrorantula the spider without faltering. Against all odds I defied Lord Triton the Lord of Water without failing. And in the Howling Wastes I punished Lord Ouroboros the Fire Tyrant himself without falling. What makes you think Iím going to stand down to the likes of you, you son of a bitch!
Badass Normal: Most of the mortal cast in the first book, but Sir Stouthorn in particular deserves mention.
Bad Liar: Sir Stouthorn. Lying doesn't exactly come with being a virtuous knight after all.
Being Tortured Makes You Evil: Not the only reason, but his torture as a slave at the hands of the diamond dogs does play a part in Andrew King's transformation into the Slave King.
Brutal Honesty: Lady Zephyr gives one to Shaw, when after having blessing his union with Showboat she declines the right of primae noctis, deciding not to sully their love with "a night of amazing sex that you could never hope to experience otherwise".
Shaw: That was a bit mean.
Cooldown Hug: Celestia offers one to the Slave King when he is on the verge of committing suicide.
Love Makes You Crazy: The Slave King does not take Little Bleu's death well. Even hundreds of years later he still obsesses over it, continually trying to resurrect her, and refusing to let it go. On several occasions this also causes him to experience very vivid hallucinations.
Love Makes You Evil: Andrew King's love for his daughter and friend are ultimately what fuels his rage and despair at their deaths, and play a large part in his transformation into the Slave King.
Celestia towards the Slave King when she asks if he is truly happy.
The Slave King again ends up on the receiving end of this, when Lady Zephyr asks him why he makes special provisions for some combatants. The idea of displaying the same hypocrisy he accuses other deities of cuts him quite deeply.
The Chains of Commanding: After worrying over whether he is turning into a hypocrite by acting in the same manner as the rest of the pantheon, the Slave King laments how much more complicated things are as of Marriage of the Slave King. The compromises he has to make actually ends up giving him a rare moment of empathy with his fellow deities.
Cut Himself Shaving: Second passes off Sombra's injuries after his torture as the result of falling down several flights of stairs. Repeatedly. Bizarrely, this actually works.
Dirty Coward: Sombra. He'll happily torture someone too weak to fight back, but the moment he's threatened by anyone more powerful will turn around and beg for forgiveness.
Fee Fi Faux Pas: At one point the Slave King attempts to locate any intruder at his inauguration anniversary, only to accidentally mingle his magic with everyone present; described as the divine equivalent of "copping a feel". In an attempt to save face, he tries to pass it off to Celestia as case of Power Incontinence and gets everyone else drunk on magically spiked wine.
First Chapter Spoiler: The prologue of The Marriage of the Slave King confirms that the Slave King did eventually succeed in bringing Little Bleu back to life, and that despite his efforts, Luna still fell to the darkness.
I Have No Son: While the Slave King generally doesn't acknowledge his children, particular mention goes to Dawson, who he flat out refuses to accept as his son. It's later revealed that this was due to Lady Zephyr deceiving him over a ritual that would produce a child, which angered him greatly and caused him to end their relationship.
I Know You Know I Know: Between Celestia and the Slave King regarding her scheme. However, the Slave King is mistaken over what said scheme involves.
Dawson hopes for this, and desperately tries to impress his father. After several false starts, he does actually manage to do this by proving his skill in combat, but the Slave King can't bring himself to admit it.
Aria similarly hopes to receive this from her father, but does get one from her mentor and father-figure Scourge instead.
The Starscream: Second, to both Scourge and to the Slave King. Unfortunately for Second, the Slave King is well aware of this even if he is allowed to carry out his schemes unhindered.
Suddenly Sober: One of the many benefits of the Slave King's Draught of Renewal.