This card, if played on turn 5 (Coin) or 6, can make every single other minion in your deck have the same tempo advantage relative to similar-cost minions that Totem Golem has. It's absolutely absurd.
However, the late arrival of the card into play (6 mana), the fact that it's a Legendary and thus one-of, and the fact it's a poor tempo play means that it's generally balanced*. It's a shame that Shaman is almost all aggro or Jade now, as that means this card never really sees play in conventional meta decks.
* The poor tempo play thing may not really be such a big deal when you consider that Overload makes most of the best Shaman cards such phenomenal tempo plays that having a single poor tempo turn shouldn't be such a huge loss. Many control decks have poor tempo turns, especially in the currently-key early game, which the Shaman class doesn't have to deal with so much.
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