Talk To Zalshum with the Brave Blade equipped to trigger the cutscene begining the quest. He'll ask you to permit him to examine the weapon, just let him.
Upon examining the weapon, he'll say, "If you've already come to be in p-p-possession of a Runic Key, you can expect great results." (THIS IS A HINT)
Acquisition of the weapon skill Atonement occurs after first breaking a "latent" by accumulating an as of yet undetermined number of weapon skill points in the usual fashion as you might have done for a trial weapon or for weapons acquired from KSNM 30 fights. However, according to antecdotal evidence possession of a Runic Key fixes the number of weapon skill points required at 250-300.
The quest ends upon trading the Brave Blade back to Zalshum after accumulating the required number of weapon skill points. A final cut scene will commence after which the wielder will now have access to Atonement.
Game Description
Client: Zalsuhm (Lower Jeuno) Summary: Self-styled leading researcher of mystical artifacts, Zalsuhm, claims that the weapon you acquired deep within Nyzul Isle conceals immense power. Wielding the now unlocked weapon will cause a magical evolution to take place...eventually.
