Lore

Duel at Ro-Lente Castle

ロ・レンテ城玉座の間の寸劇（クライム戦死）

World & HistoryBattles & Events

Vol. 14, the day the capital fell: in the throne room of the royal castle Ro-Lente, Ainz staged a "skit" with Renner and fought and killed Climb when he returned; Climb was later revived in Nazarick.

After the war began, Renner had Climb hide royal treasures in a designated storehouse, which got him away from the castle (King Ramposa III told Climb about a secret passage)
Ainz, the Guardians, and Renner had rehearsed this "skit" beforehand, aiming to convince Climb that Renner was a victim
When Climb returned to the throne room, Ramposa III was already dead
The Sorcerer King fought Climb and killed him; Pestonya then revived him in Nazarick
After the skit, Ainz gathered the turncoat Marquis Raeven and others in the ruined capital to give instructions for what would come next
Other sources state that Ainz thereby obtained the Kingdom's treasure "Razor Edge," and that the scene in which Demiurge's [Commanding Curse] forced Renner to kneel was also an act put on for Climb (unverified)