The idea is getting insane value from Unstable Form
by playing it on Felrauk the Outcast
(be careful with the last one; otherwise you'll get a 1-drop instead of 7)
It's the same concept as Feln Fasciata
but with key differences aimed at gauntlet:
The spell+ North-Wind Herald
package adds some sweet stuff for gauntlet. Condemn
for example is specially good here because there are a ton of X/1s in gauntlet and it can let you cast another cheap spell for Herald. [Condemnmarket is good in general as well because it can let you get rid of 2 aggressive units for 2 power, which wins you the game versus the gauntlet Blitz decks]
Seek powers and cutting Icaria let us get our Felrauk or Champions influence requirements more reliably. Seek power is also another enabler for 0 cost Herald.
is also an insane gauntlet card.