This is a Grixis list I've been working on since being inspired in the Multiplayer forum.Certainly not optimal and open for critique. Some choices are purely for flavor, like Ultimatum and Crosis Charm, but flexible enough. I probably also went too heavy into creature destruction, but it's a base. Games in my play group usually have between two to four players, so something that could work in small group games as well as duels would be optimal.
2 Cruel Ultimatum
3 Dark Intimations
3 Languish
3 Terminate
1 Crosis's Charm
3 Negate
1 Kolaghan's Command
3 Rhystic Study
1 Crux of Fate
3 Fleshbag Marauder
4 Baleful Strix
2 Archaeomancer
1 Keranos, God of Storms
1 Mulldrifter
4 Crumbling Necropolis
4 Drowned Catacomb
3 Dragonskull Summit
5 Island
2 Mountain
6 Swamp