I’ve been running Sindragosa as the Frozen Champions give you a legendary AND a Frost Elemental with lifesteal when in Death Knight form.

Geddon acts like Hallazeal in this deck as his AoE damage also heals Jaina in Death Knight form. So in terms of AoE damage, flamestrike works as a replacement. In terms of healing your hero, it does not. Not to mention that you get multiple AoE/heals if your opponent can’t remove him whereas flamestrike is 1 use and it’s done. I think that if you really want to play this deck, Geddon is essential. How viable the deck is remains to be seen, but I’ve had pretty decent success with it.

Any replacement for Alex? It’s the only card in the list that I don’t have.