Seize the glowing sword at the top of the spiral stairs in Stormhold at ( -150, 6, -96 ) /waypoint -150, 6, -96. An Inert Bone Bladed Claymore will appear in your inventory. Examine it to be offered the quest.
Kill Opolla, a level 42^^^ heroic gnoll shaman, inside Blackburrow. You can find Opolla directly south of the bridge, in the farthest room at ( -24, -16, 83 ) /waypoint -24, -16, 83. He will spawn and attack you as soon as you enter the room.
Examine the sword.
Slay Redak, a level 44^^^ heroic troll warrior, located in The Chapel within Stormhold. ( 88, -16, -9 ) /waypoint 88, -16, -9
Examine the sword.
Forge the hilt and blade into one.
In order to reforge the blade you must have an ebon cluster.
Go to Runnyeye in the Enchanted Lands and head down the path just past the bridge until you come across the first room with goblins past the archway, there will be another room with more goblins. Once you enter the room to the left there will be a small alcove and inside will be a forge and an anvil sitting in front of the forge. Inspect the anvil to reforge the blade. ( -10, 1, 5 ) /waypoint -10, 1, 5
Examine the sword. To get your sword you will need to slay 1,000 Sentient beings.
This means killing any intelligent monsters, such as any character race, goblins, gnolls, or lizardmen. Golems, elementals and undead are not considered sentient.
Warning: Choosing this option will remove Berik, Sword of Thunder from your inventory and you will not be able to get it back. If you have not completed Berik's Revenge then your only option is to accept the Bone Bladed Claymore.
You can obtain the Electrified Bone Bladed Claymore after you've completed this quest. By right-clicking on the forge in Runnyeye with both the standard Bone Bladed Claymore and Berik, Sword of Thunder in your inventory (but not equipped), you can choose to "Break Berik over the forge." Berik and the Bone Bladed Claymore will be removed from your inventory and you will receive the Electrified Bone Bladed Claymore. If you choose to do this, you cannot change the Electrified Bone Bladed Claymore back to the original two swords, so be sure of your decision. You can, however, purchase both Bone Bladed Claymore and Berik, Sword of Thunder from Shady Swashbuckler XVIII in Nektulos Forest, or other heritage vendors.