Are we going for theoretically balanced cards? (I'm definitely not the best developer, but destroying creatures, artifacts, _or_ enchantments for 4 generic mana is insane. Destroying all is just silly.) Anyway, going to derp around at the first few for now. (I have no idea what is 'expected', but I'm making myself design more theoretical cards when I can, so you can deal with it.
) Also, it's late, so the random feedback I'm giving isn't meant to be 'truth', but just my initial reactions (I'm curious on whether they make sense to the respective creators).
Dragonforce:
@chetoos, That's _very much_ functional change that changes a triggered ability (resulting in restrictions) to an activated one (lots of freedom and not forced to do so when your last dragon dies).
@square1, That said, it should definitely be 'if you control no Dragon creatures', because currently the Dragonforce keeps itself alive.
"""
Dragonforce RRR
Enchantment
At the beginning of your upkeep, put a 4/4 Dragon creature token with Flying and Haste onto the battlefield, then sacrifice a non-Dragon creature for each Dragon you control.
Whenever you control no Dragons, sacrifice Dragonforce.
"""
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Tool:
@chetoos, It seems a bit too universal; it's a tool, not a sonic screwdriver.
"""
Tool 1
Artifact -- Equipment
Equip 1
Equipped creature has "T: Add C to your man pool. Spend this mana only to cast artifact spells."
"""
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Blind Guardian:
@Ladsworld, A good simple design, but it doesn't immediately resonate with the name for me.
"""
Blind Guardian 3
Creature -- Construct
Defender
Whenever a creature attacks, defending player gains control of Blind Guardian.
3/5
"""
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Crush 40:
@AdmiralMemo, As I touched on earlier, the card is extremely problematic development wise. (Also, _black_ doesn't really get artifact or enchantment removal, let alone giving it to any deck regardless of color - phyrexian mana OP.) That said, I like how you handled the name. ^^
Memo's could be tweaked by just making it something similar to Dismember.
Ugh, the name is just... *ponders* so if we don't use Memo's trick... It sounds like an Un-card's name... XD (I'll come back to this one