: Mmm yes. A level where you have to (presumably) hunt
: down a fallen lord, except you don't know what he looks
: like, and won't recognise him even if you find him.
: Now THAT's a tough objective!
Ooh, idea! What if he is "Faceless" because he has no face of his own? No set appearance - he simply copies the look of someone or someTHING else. So you wind up hunting down Thrall and Myrmidons and Soulless and other such monsters, and the Faceless Man is amongst them but hangs back to the very back of those forces, and runs away when they're about to be beaten. Then later, when he has taken the form of a Trow or some more powerfull enemy, he actually tries to fight you, but when he is defeated, he vanishes and some sort of thin smoke floats away to another point, reforming into his Trow form, which stomps off into the distance...
You chase him down again, and find some more powerfull enemies, Shades or something. As you're battling them, in the midst of it all this this black smoke creeps in and forms into another Shade, who tried to fight you, but dissapears into that black smoke again, which races of into the distance...
But now, when you follow down the direction that this smoke went to, you wind up in a forest of dead, dried trees, wandering through these paths looking for something, and then out of the blue one of the trees (a Changeling) jumps out and attacks you! You kill it, but when it dies a thin ring of black smoke dissipates out into nothingness. One of your units asks, nervously, "I... is he dead?", but gets no response.
All of the units would be named "The Faceless Man" and have various flavor texts explaining his nature.