I've created this deck to beat Jekk, it was not an easy fight but did it in the first try.
Ruin followed by
Lightning Storm is the best way to do it, use the spells to control the board and go playing the creatures when needed. There're many burn cards to control the creatures and do some damage to him.
Thunderstrike Dragon made me win the game.
Notice: the creatures used aren't optimized, the only creature that is realy good on this match is
Furnace Mage, I only used what I had in my collection.