I think some of you guys might be over thinking it. Elend has grown up and matured, and this chapter shows it. We know there were more bands of random, raging koloss wandering the Final Empire than just those from the army that hit Luthadel, and it makes sense that one of the first things Elend & Co. would do is to stop them, and build up his own side to defend his people from the other Dominances and the forces of Ruin.
As for him being a tyrant, he would come to that conclusion after his earlier attempts at a more democratic government nearly ended in disaster. Democracy (as has been well illustrated on our own world) does not work well in a war zone. For the good of others, Elend will be a tyrant. I just hope he doesn't grow to like it.
If this is just a ploy to trick people into following him by suddenly "stilling" the koloss, I think that would be out of character for Elend. I have faith that, inside, he's still an idealist. He's just an idealist that's had a heavy dose of harsh realism pounded in, now.
And facial hair, depending on how he wears it, can look tres cool.