I wont add dragon aspects, at least by now. But lk can rise Frost wyrms, the strongest air unit. Also, once lk merges, u can rise elite frostbrood from sindrsgosa fall (and sindragosa as demi). I dont want more drakes. Btw "scourge" is barov faction after plague unleashed. And they can kill several heroes to rise them as uds. Lk faction (vrykul, ud nerub, in northrend) is lk (yep, im quite original ).