Eternal Skylord is basically Aven Eternal on steroids. It has bigger Amass and it gives flying to your zombie tokens. It also costs five mana, but that is a decent price for such a strong card.
If you already have a zombie token on board, then it just grows by two +1/+1 counters and attacks in the sky, which is a winning scenario in most cases.
Too bad the Skylord doesn't have flying himself, but that would probably be too much for an uncommon card.