Divine Might II

Divine Might II battlefield is the source of Rem's Tale Chapters 6-10 for Reforged Armor +1, synthesis materials for Reforged Armor +1, as well as high-Item Level equipment.

Pentacide Perpetrator Phantom Gem key item is required to enter. They can only be acquired by players level 95+ who have completed all of the Ark Angels II fights on NORMAL difficulty. The gem can be purchased from the following NPCs for 30 Merit Points:
 * Trisvain in Northern San d'Oria (J-7)
 * Raving Opossum in Port Bastok (J-11)
 * Mimble-Pimble in Port Windurst (L-5)

Difficulties and Rem's Tale
The battlefields come in three difficulties:

Source
http://forum.square-enix.com/ffxi/threads/38764-Dec-11-2013-%28JST%29-Version-Update