This clever Silvan Lore hero arrives with a fairly modest set of attributes to befit her low threat cost. However, Rossiel is extremely quick to master the challenges she encounters, and she gains two extra Willpower whenever the active location shares a Trait with a location in the victory display. Likewise, she gains two points of Defense Strength whenever she defends against an enemy that shares a Trait with one in the victory display. You may not always benefit from her abilities, but when you do, Rossiel becomes one of the most capable heroes in the game, with an effective Willpower of four, Attack Strength of one, and Defense Strength of four – all for just eight threat cost.
Naturally, Rossiel will want to take advantage of the event Leave No Trace to force locations into the victory display. Later on, she'll also hope to make good use of None Return to force enemies with the appropriate Traits into the victory display, as well. Still, even before you can get your hands on None Return, you can explore the new tactics afforded by Rossiel and her victory display manipulations with such cards as Scout Ahead and Out of the Wild.
There's no better place to start experimenting with Rossiel and her unique tactics than within the dungeons of Mount Gram. Here, she is guaranteed a couple turns to take advantage of Secrecy, and your ability to manipulate the encounter deck and victory display can help her free the rest of your fellowship… a matter that becomes especially important once you've made your way to the third quest stage and Jailor Gornákh sounds the alarms!
-Uncredited. Posted to the FFG Website 7/30/15