This article will guide you on how to kill Nere Easily in Baldur’s Gate 3. When you find Runepowder, use it to demolish the rubble. Return to the cave where Nere is stuck under rubble.
Speak with Elder Brithvar and persuade him to betray Nere. Then throw the Runepowder on the rubble. Let all your party member walk away before igniting the power with fire. Even if you do not remove the scrying eye, you will get the opportunity to request that Elder Brithvar betray Nere.
Once Nere is free, start a conversation with him where you can decide whether you want to attack Nere or choose to side with him.
If you choose to go against Nere, Elder Brithvar will declare his revolt against him and the rest of the Duergar. Half of the Duergar troops will also join you. A fight will break out and you are fighting Nere and the non-rebellion Duergar soldiers.
After your triumph and Nere’s death, you can persuade Elder Brithvar to liberate the slaves and gain a substantial sum of wealth. This will also clean up the Grymforge.
If you did not destroy the scrying eye, Elder Brithvar will ask for coins after the battle.