Anti-Sorcerer Kingdom Alliance

Anti-Sorcerer Kingdom Alliance is a hypothetical coalition of several countries set to counter the growing power and influence of the newly-founded Sorcerer Kingdom.

Background
It is an alliance that comprises of different nations on the New World continent who acts as an opposition to the Sorcerer Kingdom. In this alliance, countries are looking to combine their forces together cooperatively and militarily to work on stopping the Sorcerer Kingdom. They viewed the Sorcerer Kingdom as the biggest threat that endangers the lives of surrounding countries.

The Magic Caster of Destroy Arc
After the Baharuth Empire propose a false alliance with Nazarick, they under Bloody Emperor Jircniv's rule silently seeks to form a grand coalition with other countries, aimed at defeating Ainz Ooal Gown and the Sorcerer Kingdom it plans to make. Particularly, Jircniv wants the Baharuth Empire, the Re-Estize Kingdom, the Slane Theocracy, the Argland Council State, the Roble Holy Kingdom and other countries so forth to come together in an alliance, where they can defeat their common enemy. Jircniv orders his imperial servants to secretly prepare for the survival of humanity and the world.

The Ruler of Conspiracy Arc
On one such secret exchange, he learns that the High Priests and representatives from the Slane Theocracy have agreed to meet with him secretly at the Grand Arena. During this secret meeting with the emissaries of the Theocracy and the high priests from the temples, Jircniv is planning to establish talks about having the Empire side with the Theocracy. However, before he could conduct talks, Jircniv is left utterly shocked by discovering the presence of Ainz Ooal Gown in the Empire and him being the Martial Lord's challenger in the Grand Arena, where his meeting was supposed to successfully takeoff. With the Sorcerer King in close vicinity of their back-door meeting, the Slane Theocracy opts to abandon it. The High Priests nearly follow suit but are prevented by Jircniv who pleads them to wait and watch the fight between the Go-Gin and Ainz happen, hoping to see the undead lose while finding its weaknesses. Sadly, not everything went according to his plans or expectations as it was the Martial Lord who ended up losing in the end. When Ainz finally went to confront the emperor directly, Jircniv realizes that it is no longer possible for the Empire to establish an alliance with the Theocracy, seeing that all his possible allies vanish before him.

The Witch of the Falling Kingdom Arc
Prince Zanac and Princess Renner hold a discussion on whether to abandon the plans on forming an alliance with the Argland Council State. According to them, while the creation of an alliance is currently in progress, they felt the situation isn't looking great for the Re-Estize Kingdom. Though a Dragon Lord from the Argland Council State has agreed to it, the two are still in need of more time to convince the representatives of the other races. Even if this falls through, they believed that the prospect of an alliance would not be completely ruled out, that much was said. They described that the Anti-Sorcerer Kingdom Alliance was forming at a snail’s pace, but progress was going smoothly nonetheless. The Re-Estize Kingdom was at the stage of relying on the generosity and solidarity of other countries to hopefully get them to sign the mutual reinforcement pact at all costs, in other words, it was an unreliable relationship without written agreements. Something like that could not be publicly announced as a military alliance. There were simply so many things to do and prepare for in order to form a tight alliance against the Sorcerer Kingdom, they would need at least a few months to have it sorted out.

Strength
So far, no information has been revealed about who is going to be joining the Anti-Sorcerer Kingdom Alliance.

Trivia

 * Bloody Emperor Jircniv was unsuccessful on creating an Anti-Sorcerer Kingdom Alliance with the Slane Theocracy due to the interference from the Sorcerer Kingdom, particularly the Sorcerer King Ainz Ooal Gown.
 * Before the Baharuth Empire became a vassal state to the Sorcerer Kingdom, the fact that Jircniv suggests having a non-human nation like the Argland Council State into the alliance composing of namely human countries mentioned by him presumes he was likely also trying to get more non-human countries to join as well.
 * According to Maruyama's conversation with the interviewer, there are multiple countries in the middle of the continent and that they will eventually make an alliance. He said they will work together to fight against the Floor Guardians in a huge war.
 * Maruyama noted that if he ever expands the Overlord Light Novel to 30 volumes, it would get into the war with the alliance of countries in the center of the continent. Maruyama stated that he doesn't want to push for more volumes because then he'll end up having to write about the war with the alliance of central countries.