I have always liked Rossiel. This is my latest incarnation of a Rossiel deck. The keys for her are getting cards into the victory display quickly, and that means paying for them. Secrecy accomplishes that by allowing for Resourceful and buying time before you are forced to engage enemies.
Between Elronds Council, Scout Ahead, Keen as Lances, and Gandalf, I find I can stay in Secrecy for many turns in most games. If I’m already set up, Keen As Lances can then be used for card draw or resources. A copy of Resourceful on Glorfindel is almost a must.
In test games, Gleowine is actually one of the most important cards. The steady card draw is critical, and Over time I upped the number of copies of Gleowine in the deck to ensure I can find him and keep a copy on the board.
The one area this deck can struggle is killing enemies, especially in the early game, before you’ve gotten set up. Treebeard, Riders of Rohan, and Ithilian Lookouts help, but those take time to get into play.
What about Folco Boffin and Strider instead of Mirlonde ?