Clayman/Chronology

Forest Disturbance Arc
Clayman was the true mastermind behind the Orc Disaster incident, hoping to gain a puppet Demon Lord to help give him an edge against other Demon Lord. He helped Gelmud and introduced him to the Moderate Harlequin Alliance.

Demon Lord Attack Arc
Clayman shared the news about the Orc Disaster incident with 2 other Demon Lords, which is Milim Nava and Carrion. Later they are joined by Demon Lord Frey when Milim invited her.

After his plan failed, the Demon Lords agreed to abolish the nonaggression pact over The Great Jura Forest and to each sent out their own forces to gather info upon the new powers rising in the forest. He chose to send out Mjurran to spy on the victors of the Orc Disaster incident.

He then received news from Tear that Frey is worried about the return of Charybdis. He chose to manipulate the beastman Phobio to be the new host of Charybdis so that it may attack Milim who was residing inside the Jura Tempest Federation. His plan succeeded as Milim managed to defeat Charybdis, earning him a favor from Demon Lord Frey.

Demon Lord Awakening Arc
Clayman started plotting a war between humans and monsters wanting it to result in Tempest's demise, and to collect the souls to awaken him into a True Demon Lord. He ordered Mjurran to cast a great magic spell to create an anti-magic barrier so as to isolate Rimuru City from outside contact. However, his plan failed when Rimuru Tempest managed to destroy the army of the Kingdom of Falmuth and became a True Demon Lord.

Clayman was also plotting the end of the beastmen, ordering Milim to destroy Carrion and his country. In order to control her, Clayman used the orb of domination, that he received from Kagali, on Milim. Afterward, Clayman threatened Frey, who claimed that she paid off her debt, to keep following his orders lest she becomes Milim's next target.

The Octagram Soars Brightly Arc
Laplace came to warn Clayman about the recklessness of his actions, but Clayman chose to ignore his friend's warning and attacked Eurazania, after Milim's independent action of giving Eurazania an advance notice of her attack causing him to be unable to kill even a single citizen as many of them had sought refuge in Jura Tempest Federation.

Falling for the scheme that the participants of the Man-And-Monster Conference came up with, Clayman believed that Rimuru is actually weak and only used Veldora's resurrection to proclaim himself a Demon Lord, consequently Clayman called for a Walpurgis Banquet in order to put Rimuru down. However, to his surprise, Demon Lord Ramiris asked for Rimuru to be able to attend the banquet himself and other demon lords agreed to this decision.

Clayman sent his army along with Milim's followers, the Dragon Faithful, to attack the Jura Tempest Federation, while he went to the Walpurgis Banquet. However, his plan was revealed and he was betrayed by Milim and Frey who explained that his orb of domination had failed to work on Milim. After being manipulated by Rimuru into pseudo-awakening himself, Clayman managed to get stronger, but that was within Raphael's calculations, so he ended up defeated and killed by Rimuru Tempest.