Now this is an OP defender! Repeatable impulse, plus repeatable ground stall! Thalys is designed to make late game decks work by preserving life totals through to the late game, hitting every land drop along the way. And this works with his flavour (kind of), since he's the guy who acts as gatekeeper to all the giant mysteries hidden in the library.

The fact that he's legendary isn't really a problem because I'm going to make a tutor for cards with defender (really hoping to make defender.dec a constructed possibility for this set). Also having four of them isn't that big a deal since you can just impulse them away (I should mention that I changed the impulse effect from 'put them on the bottom of of your library in any order' to 'into the graveyard.' This is to synergize with the reanimation theme in black; also, I had this crazy idea that milling yourself to death should be a real danger for late game decks).

Here's a templating convention I don't know: when you have a legend with a long name, are you allowed to shorten that name in the rules text (from Thalys, Protector of the Architectonic to Thalys)? I could have sworn I saw somewhere recently that this was allowed, but I haven't been able to find any concrete evidence.

Nice card!

The way Legend names work is that they spell themselves out in full the first time they appear on the card. Second and subsequent occasions, they just use the short name. My substitutions ~ and CARDNAME are actually smart enough that they do that automatically :)

Cool, that's handy. In the end, though, I'd say Thalys needs a shorter name. As it is, his title is pretty scrunched.