Afterglow

Afterglow is a beneficial Status Effect in Final Fantasy XI only available to those in a Party with a player who is wielding a Relic Weapon, Mythic Weapon, or Empyrean Weapon that has been upgraded to its absolute maximum possible extent and glows with power, or a shield of similar power (Aegis Shield or Ochain). When that player uses their weapon's special Weapon Skill (or the job ability Shield Bash for Aegis and Ochain), they will for a brief time become the center of a Sphere-type effect. Party members within the effect gain this status. The weapon user themselves will instead get Aftermath status, which overwrites and prevents Afterglow.

The actual effect of Afterglow depends on what type of ultimate weapon or shield is being used.
 * Relic weapon Afterglows give increased Accuracy and Ranged Accuracy.
 * The relic shield Aegis's Afterglow gives -5% Magic Damage Taken.
 * Mythic weapon Afterglows give +15 Attack and Ranged Attack.
 * Empyrean weapon Afterglows give +5% Critical Hit Rate.
 * The empyrean shield Ochain's Afterglow gives -7% Physical Damage Taken.
 * Neither the relic instrument Gjallarhorn nor the empyrean instrument Daurdabla is capable of bestowing Afterglow or Aftermath at all.

Trivia

 * When first implemented on the Test Server, the trials to upgrade a mythic weapon to Afterglow level required 500 Mulcibar's Scoria, which drop one at a time from the infamous Pandemonium Warden. According to one widely circulated calculation, this would have taken 26,000 hours--three years if done 24/7/365, or ten years if done as a paying job by a workaholic.
 * After great outcry, Square Enix decided to lower the number of Scoria required to 150, and more importantly, dramatically boost the Zeni earning rate.
 * Upgrading a relic weapon to Afterglow level originally took 1,000 Umbral Marrow, which drop one or two at a time from Arch Dynamis Lord. Following the outcry above, Square Enix reduced this to 250. General player consensus has it that this isn't worthwhile either, although at least a couple of people have done it anyway.
 * Upgrading an empyrean weapon to Afterglow level requires 3,000 Riftcinder or Riftdross from top-tier Voidwatch monsters.