Dark Legacy of Evard by Richard Baker, is the adventure for Season 5 of D&D Encounters. It was released for play in Spring 2011.
As with the previous two seasons, Dark Legacy of Evard continued to tie into the Essentials line for D&D 4e. As a result, the pregenerated PCs are all Essentials builds—the exact same characters from March of the Phantom Brigade, as it happens. However, this season of Encounters also ties in with Player's Options: Heroes of Shadow (2011), which was Wizards' first post-Essentials release, supporting both Essential and classic 4e builds. Heroes of Shadow featured Evard as the creator of shadow magic in the Points of Light world, so he was a natural focus for this adventure. Dark Legacy of Evard also tied in with another shadowy sourcebook: The Shadowfell: Gloomwrought and Beyond (2011).
This new season of Encounters didn't include an explicit homage to an older D&D adventure, as the previous two seasons had. However, Evard was actually quite an old name in D&D. Evard had first been mentioned as the originator of Evard's Black Tentacles, which dated back to Dragon #67 (November 1982). Just a month later, in Dragon #68 (December 1982), Gygax explained that Evard was an NPC from the Greyhawk campaign. One of Evard's spell books was described in Dragon #82 (February 1984), in an article by Bruce Heard, but Evard still didn't get as much attention as most of Greyhawk's wizards during the AD&D days.
That changed a bit with the release of 3e. Evard was mentioned as an enemy of Mordenkainen in an article by Erik Mona and Gary Holian that appeared in Living Greyhawk Journal #0 (August 2000) and also received a mention in the Living Greyhawk Gazetteer (2000). Then in Dungeon #107 (February 2004), the Paizo staff (finally) gave Evard a full write-up as a "Critical Threat." Evard's inclusion in Heroes of Shadow and Dark Legacy just continued his upward trend of recent years.