Join the Blade of the Darkmoon covenant, and achieve rank +1 by offering 10 souvenirs of reprisal to Dark Sun Gwyndolin. This miracle may only be obtained once per character, regardless of playthrough.
Players must be in the Blade of the Darkmoon covenant to use Darkmoon Blade; they must also have a talisman equipped on the left hand and an enchantable weapon on the right. Darkmoon Blade adds Magic damage for one minute. Damage increase is initially 1.8x of the magic adjust of the equipped talisman, increasing by 0.1 with every rank gained in the covenant. At the highest rank, Darkmoon Blade has a 2.1x boost—making it potentially the strongest weapon buff in the game.
Darkmoon Blade is an extremely powerful weapon augmentation that massively increases the damage output of a player. It is a great buff to use against bosses and against other players. However, given its requirements usage can be limited. For example, it is impossible to PvP as part of the Path of the Dragon covenant and use this buff. However, players may still use Darkmoon Blade together with Cracked Red Eye Orbs.