Speak to Anne outside the tomb at Duskburn

-753, 81, 718

Walk up to the entrance of the tomb to destroy the wooden board

Descend down and watch out for any wild ghost type pokemon

Once you've reached the bottom there will be a strange figure in the center of the arena

After learning his name, defeat him in a Pokémon battle

Lord Fayette VI

• Level 100 Absol
• Level 100 Rotom
• Level 100 Drifblim

Enter into the portal, but first fight a Dusnoir that is blocking the path

• Level 105 Dusknoir

Parkour across to the other side

Find Lord Fayette on the larger island

Defeat Giratina (Fayette can heal your Pokémon)

-Level 110 Giratina

It will teleport you back to the overworld and you'll have to fight Sir Fedrick Samuel Elmerton IV

Sir Fedrick Elmerton IV:

• Level 100 Gengar
• Level 100 Spiritomb
• Level 100 Froslass
• Level 100 Honchkrow
• Level 100 Houndoom
• Level 100 Tyranitar

Return to Anne for rewards and to 'complete' the quest

You can obtain a spell tag from talking to Lord Fayette VI again