I think I came up with the optimal answer for Amaz's scenario where your opponent has 30 health and 970 armour and no cards, and you need to deal as much damage as possible with any four collectible cards in your hand and ten mana to use on them. You have perfect control over RNG.
Lorewalker Cho + Unstable Portal + Mind Vision * 2
Play Lorewalker Cho (2 mana). Play Unstable Portal (3 mana, total 5 mana), which gives you a Sorcerer's Apprentice. Play it (0 mana because of discount, total 5 mana) Play Mind Vision (0 mana because of Sorcerer's Apprentice, total 5 mana) to get Unstable Portal from your opponent. Play Unstable Portal (2 mana because of Sorcerer's Apprentice, total 7 mana) again to get a Warsong Commander, and play it (0 mana because of discount, total 7 mana).
Infinity times, play Mind Vision and get a free Mind Vision from your opponent because we have perfect control of the RNG.
The infinity plus 1th time, get Unstable Portal from your opponent instead. Play it (2 mana, total 9 mana). Get Edwin VanCleef, play him (0 mana because of discount, total of 9 mana). He gets 2 + infinity*2 attack, and apparently gains Charge from the Warsong Commander because that card checks his base stats, which are 2/2. Attack with him.
This reminds me that I figured out how a mage can kill you from 30 health in one turn in arena starting with no board, zero cards and only the draw to work with (prompted by Amaz saying it was impossible to die one day when he was at 18 health).
Going first you'll have to draw 12 cards before turn 10. So on turn 10:
13. 3 mana Arcane Intellect->Arcane Intellect, Sorcerer's Apprentice
14. 5 mana Sorcerer's Apprentice
15. 7 mana Arcane Intellect->Arcane Intellect, Sorcerer's Apprentice
16. 9 mana Sorcerer's Apprentice
17. 10 mana Arcane Intellect->Arcane Intellect, Unstable Portal
Everything from here out is free.
18. Unstable Portal->Sorcerer's Apprentice
19. Arcane Intellect->Arcane Intellect, Unstable Portal
20. Unstable Portal->Sorcerer's Apprentice
21. Arcane Intellect->Arcane Intellect, Fireball
22. Fireball 6 damage
23. Arcane Intellect->Arcane Intellect, Fireball
24. Fireball 12 damage
25. Arcane Intellect->Arcane Intellect, Fireball
26. Fireball 18 damage
27. Arcane Intellect->Fireball, Fireball
28. Fireball 24 damage
29. Fireball 30 damage
Leaving him with 1 card in the deck.