Effective Possessed

Is this an oxymoron? Or is there a way to make good use of Possessed?

My original thought was to use them in the way that many players use Khorne Berserkers, with Plague Marines and Noise Marines as my troop choices. If I went this rout, how would I best use Possessed? I can't decide which Icon works best for them--Khorne to give them yet another attack, Nurgle to make them harder to kill, Slaanesh so they have the same advantage Berserkers have on the turn they charge except for every round of close combat, or if I should keep them on foot in a unit of 20 with an Icon of Tzeentch to keep them alive to tempt ordinance away from things that actually matter, or if there's something else I hadn't considered.