Hearthpwn

Quote from Devizz >>

All Will Serve is a deck thinner which might not always a good thing if playing against another control deck. Also, you trade 1 card for another which is nothing, for 1 mana - that is is a slight drawback. 

That is not quite right. 1 mana draw a card is not a drawback, as you are thinning your deck. If you pay 0 mana to draw, that is an insane advantage.

I  give you the example of the pre-nerfed Flare. It used to be 1 mana and every single Hunter deck ran it since it was just extremely powerful deck thinning. 

If you look at the old Power Word Shield, technically, it breaks this rule, but it requires a minion to play so therefore, not all Priest decks are able to play this card.

Furthermore, look at all the control decks in existence in Standard at the moment. Not a single one wins by grinding to fatigue. There is absolutely no reason not to play All Will Serve.

Couple of "errors", though that is not quite the correct word:

• Twinspell is an expansion-exclusive keyword, you can't use it. It also does not exist in the Basic set.
• No basic set uses a class-specific keyword. Therefore, you cannot use Syphon in your Basic set.
• Same thing with Silence, it does not appear in the Basic set.

As for balance (I skimmed quickly though, probably didn't catch everything):

• I think your Hero Power is way too complicated. If anything, DH has shown us simplistic Hero Powers are the way to go.
• All Will Serve is a 1 mana draw a card, no drawbacks whatsoever. These are typically not printed in Hearthstone, as they turn a deck from a 30-card deck into a 28-card one. (That is, they are auto-includes)
• Sapphiron is awful. Very low impact, and you have no control over what it freezes.
• Succor is a very strange card from a design standpoint. You have absolutely no cards that activate on discard, nor benefit from it. Discard should probably be left as a warlock thing.