Just posting the deck I used to #Ruin Jekk. It's budget because I'm new to Eternal, replace Navani with another permafrost, in fact I would make place in there to have 4 Permafrost.
I assembled this deck by reading reddit posts, hope it helps, he won't get BIG threats but wait until he plays a weapon on the minion to Permafrost it, Stun or Vanquish it.
The match will come to a stall place because he keeps the preasure on, but it will be properly countered or stunned, in my case Elder's Feather was my top deck winner into an already buffed unit.