I recently completed this quest using a fairly cheap deck:
Double Clay X 3
Treacherous X 3
Shadow Idol X 3
Shadow Tentacle X3
Shadow Cape X 2
Fallback X 1
A couple of things to note before I go into my strategy:
1. Shadow will not play shadow spells if you have
Shadow Idol in play
2. Shadow will not play cards if it would cause him to deck out.
Armed with this information I proceed into strategy:
Turn 1
Buffing defense and playing
TreacherousIt is important NOT to play
Shadow Idol on the first turn. The reason for this is that you will need a turn free of damage later on to survive long enough to mill him to death. If you play
Shadow idol on the first turn you effectively lose a turn on not taking any damage. I notice Shadow tends to play spell damage on turn 1 so the damage you take will be minimal compared to the damage he can do with his physical attacks. (Note if you were unlucky and didn't pull any
Double Clay in your opening hand feel free to play
Shadow TentacleTurn 2
Shadow IdolNow is the time to play
Shadow Idol. The beauty of this turn is that if you played
Treacherous last turn and haven't discarded (which you shouldn't do!) It will play for free this turn due to Artrezil's ability getting you closer to milling Shadow to death.
Turn 3,4,5,6
DEFENSE!
From here on out Shadow will know better than to try to attack you with magic so do your best to buff your defenses using
Double Clay Shadow Cape and
Fallback. It shouldn't be necessary to cast
Treacherous again as it will activate due to Artrezil's ability
With your defense high (at round 3 I was lucky enough to have about 13) and his attack debuffed by
Shadow Tentacle you should be able to outlast him until he is out of cards.