"What cards would you change out?"
The following enchantments are useless for [mwcard=MWSTX2FFC10]Sardonyx, Blight of the Living[/mwcard]
[mwcard=MWSTX2FFE02]Akiro's Favor[/mwcard]
[mwcard=MW1E01]Bear Strength[/mwcard]
[mwcard=MWSTX2FFE06]Lion Savagery[/mwcard]
All the healing can´t help him either.
I think you are going to be starved for actions and mana with this book.
(So i would cut most of the creatures)
I would start with [mwcard=MWSTX1CKC06]Guardian Angel[/mwcard] and a [mwcard=MW1J04]Battle Forge[/mwcard].
Adding Armor and an Enchantment Ring. (but the Dragon would "never" come into play)
cut:
[mwcard=MW1I22]Resurrection[/mwcard]
add:
[mwcard=MWSTX1CKE03]Healing Charm[/mwcard] (insted of Minor Heal)
[mwcard=MW1E29]Nullify[/mwcard]x2 (I would hate any enchantment/incanation on my dragon)
[mwcard=MW1E32]Regrowth[/mwcard]
maybe a couple of
[mwcard=MWSTX1CKE04]Enchantment Transfusion[/mwcard] to protect the Dragon or to load enchantments on the enemy mage.
"What Mages/Book builds will be the most challenging for this design?"
Almost all of them. Winning with this book will be very hard.
Turn 1: (20)
Guardian Angel (12)
Battle Forge (.
Turn 2: (10)
Enchanters Ring (1)
Enchantment (1)
Sunfire Amulet (6)
Turn 3: (12)
Leather Gloves (1)
Enchantment (1)
Hand of Bim-Shalla (5)
Turn 4: (15)
Leather Boots (1)
Enchantment (1)
Enchantment (2)
This is going to be really slow and the Dragon would only come out at Turn 6.
Turn 1: (20)
Enchanters Ring (2)
Regrowth (1)
Turn 2: (27)
Sardonyx (24)
Nullify (1)
Seems more fun.