Wow knowledge can be extremely helpful in this theme contest as elite must stay with their origin otherwise you be off the theme. While warcraft 3 and wow doesn't fully share their lore, they still give you a further sight how a unit you would see in warcraft 3 can be advanced in the wow counterpart.
Don't be afraid if you are stuck with lack of idea how to make it a final form to them. Do some research, get inspired, you will be okay.
Now you probably thinking: "Well shido, this contest now only relying on poll votes meaning no matter how close their origin to their normal encounter, they don't care, they just care which one look prettiest."
Yeah, i'm fully aware that, you would argue someone can go fully off the theme and people still end up voting higher than they shouldn't be. I don't know about that last part and you are capable to open up an arguement. Seriously, do your best.