Avalanche Watcher is pretty good for atlantean decks. It's effect means you are always have something to use up all your mana with. From 1-5 mana you get an on-curve creature 1/2 upto 5/6, past 5 mana it falls off hard 7m for a 7/8 isn't great. Mostly being a good filler atlantean for the deck.
RE: Will Fun Deck Become Meta When Avalanche Watcher Released? How to Play Avalanche Watcher