I like this cycle, but this doesn't follow the pattern of granting a keyword ability. In addition, this, Draconia, Firebreathing Kingdom, and Unferno, Marsh of Bones sound legendary, but Elf City-Tree and Architect Falls don't.

Mmm. I'd also argue that the Elf land and the Wizard land are far above the curve for that reason. I'm not a fan of making lands better than basic lands, but, if I was to agree that a very minor enhancement was fine, I'd be flummoxed to see an island that tapped to counter any spell that targeted creatures you control (which is roughly what Architect Falls does). But giving a mild bonus to a creature that you had to work to put into play? Yeah, I can get that.

On the flip side, I don't think the 4 keywords, one not is such a terrible thing. If I had my way, I think I'd like one more creature to change out the keyword for another non-, though.

I totally missed that there wasn't a drawback. And unlike Eiganjo Castle, I don't think making it legendary counts as sufficient drawback.

This is pretty crazy. It seems like it should have some sort of cost or drawback, that's for sure.