Gelmud/Chronology

Forest Disturbance Arc
For 300 years, he had been planning to create a species war by naming certain monsters born from the goblins, lizardmen, and other such races. Having this plan in mind, but lacking the resources, Gelmud contacted with Demon Lord Clayman and was later hired by him.

Enlisting support from one of the Demon Lords, his plan was slowly unfolding. He was methodically heating up the situation between monster habitats of the Great Forest of Jura. When you name a monster, besides simply powering up the monster, it also means increasing the number of subordinates who are loyal to you. Since monsters have an unspoken rule of preying on the weak, they swear allegiance to the strong. Gelmud thinks that since he names his subordinates himself and grows them himself, even if his subordinates become Demon Lords, they will naturally remain his loyal subordinates. The method is servile, it's petty, and it doesn't seem to be a straight attack, but it's planned and solid, and Gelmud has a series of names as part of his career plan to become a Demon Lord.

However, Veldora's disappearance caused his plans to spiral out of control because of the increase in monsters activity, so he was obligated to improvise, in order to not die from the hands of his employer - Clayman, who invested a lot of resources into the plan and would be upset by failure. By new improvised plan Gelmud had to create a Demon Lord from the Orc tribe, and control them into starting the war.

When the time came, however, a slime named Rimuru quickly gained control over Jura Forest and formed an alliance with the creatures of the forest to fight back. Enraged, Gelmud enters the battlefield, and rants about how the alliance ruined his plan. Under the Starved skill, the Orc Lord Geld decapitates and devours him.