This was a tough one, indeed,requiring a great deal of imagination!
So here is the solution everyone:
- The card in our hand are [Netherspite Historian] and [Faerie Dragon]
- We trade the [Mana Wraith] into a [Sunwalker] and kill it.
- After that we play the [Netherspite Historian] for 1 mana and we pick [Nefarian].
- [Nefarian] is played for 9 mana and gives us a [Sacrificial Pact], so we can kill [Lord Jaraxxus] on the spot!