Yeah, this is fine. Kinda amusing to imagine someone with ten of these on the battlefield, but they've either had to spend 10 cards on it, or they've been doing something strange (Artificer's Intuition a lot followed by Open the Vaults, maybe?) so it's fine.
I like this, but I would take off the clause about landwalk. It doesn't really fit the flavor. Also, you're treating unlockable as though it's a keyword ability, which it's not. Cards now read "~ can't be blocked" in order to make that more clear.
Done
This is actually not one of mine, this is from Warrior Withins cards. You can find them in the link under the geeral description for the set.
Hmm. How do I word it so that it doesn't allow you to block flying creatures?
Yeah, this is fine. Kinda amusing to imagine someone with ten of these on the battlefield, but they've either had to spend 10 cards on it, or they've been doing something strange (Artificer's Intuition a lot followed by Open the Vaults, maybe?) so it's fine.
I like this, but I would take off the clause about landwalk. It doesn't really fit the flavor. Also, you're treating unlockable as though it's a keyword ability, which it's not. Cards now read "~ can't be blocked" in order to make that more clear.
No, I don't think so. It's a very nice interpretation.
I think that these abilities would be in the opposite order.
Very nice implementation.
I'm surprised that this doesn't destroy walls.
hmm. That's a good point. Perhaps make it run on charge counters, in the same fashion as the Missile Launcher?
Colourless Pestilence that costs
+
to set up and keeps one of your creatures tapped but alive?
I, um, well,
isn't strictly better than 
but you've very nearly obsoleted a card that got removed as being too good.