Mono Lore Grima will be awesome but Grima with Spirit should also work well. The Galadhrim's Greeting for 2 is not bad at all (net threat reduction of 5).
I think Grima is good, but it's important to remember that "Whenever Doomed cards are played, EACH player must raise his threat by the value of “X.”" (emphasis added). So, in solo play, you have no one to piss off. Raising the threat of all your buddies? That could get ugly...especially if they have no threat reduction.
Combine these two posts for an interesting point. Raven's post is only true for 1-player games. In a 4-player game, you cut Galadhrim's Greeting's power in half (lower everyone by 2 after raising everyone by 1) or worse (if you choose to lower 1 player's threat by 6, for a net lowering of 2 threat). Might as well pay the full price of 3 resources for 6-8 threat loss in a 4-player game.