I'll talk about airhood here:

Making flying matter is dangerous enough. Flying is a wonderful ability in Limited. If it matters, you are tempted to design many flying creatures. Colors that can't have them pretty much have to face unblockable creatures and try to race them. Of course, this can be solved.

Now that you make flying matter, of course it's cool to have cards that upgrade when you control creatures with flying. But there are some big problems:

-You don't want to play non-flying creatures. And this isn't like putting Moriok Replica in your infect deck, because he still does plenty of stuff even if it can't "really" damage your opponent. Here, having a non-flying creature actively makes your cards worse.

-You can't possibly have an all-flying creature deck in Limited. That means airhood won't be always active. That's cool. The bad thing is that with metalcraft, for example, you try to have more artifacts while your opponent tries to deal with them so that you don't reach three or more. Here, you fight with yourself. Should I lose the bonus to develop my board? Should I stop playing creatures so that Condemned Spirit keeps its protection?

-Even if you try to control it, creatures don't leave the battlefield because you want to. So, even if you get past the fighting-yourself problems (by being a good player), you will find situations you can't control. If your opponent is smart and the airhood bonuses are relevant, he or she will go out of his way to not deal with your nonflying creature. And you'll be frustrated because you'll be playing your cards the way your opponent wants to.

The cards with airhood are good without airhood. It is just a bonus and in limited if you get airhood then you have a slightly advantage. But playing more creatures will almost always be worth of losing airhood. All in all I like that "fighting with yourself" description. What I meant to create was a skill-testing ability.

I know what it can do. It plays well enough and you can make an airhood-theme deck in Constructed if you like. No problem (save for awkward deckbuilding decisions).

What I don't like is that you may open your booster, find , say "Hey, this is cool.", and then find it doesn't really work the way you think. It's as if the ability was lying to you.

About this card in particular, the airhood effect is cool, but I'm not sure if it wants to be in this anthem. The fact that you have a flying-matters theme means you want an anthem. But your anthem costs one more than the general Glorious Anthem. :/ Maybe the second ability is enough to excite the rest, though.

This card is so crazy that I can envision it being used in creatureless decks. 0 out of 0 will vacuously satisfy airhood, after all, and it's a lot less vulnerable than Worship that way.

Not really. If you have an empty set of creatures, whatever statement you make about them is false.

Logically, everything is vacuously true about the empty set. Noncreatures with airhood should have an escape clause: "When you control no creatures, sacrifice ~."

Yeah, dude is right. It's the reason why all those cards from Prophecy say "If you control no untapped land". If you have no creatures, all of them have flying. All of them don't have flying either, because all of zero is zero. It's very strange grammatically, but true mathematically.

On the subject of airhood... I like it, though I'd also warn any designer to hit it to be careful. I remember what the bird tribe was like in Onslaught block... no matter what you tried to do with it, it always became about racing your opponent. Shadow in Timespiral, though, did a good job showing that you could work around a theme like this, as long as you were willing to turn most of the evasive creatures into utility creatures instead of efficient beatsticks. Obviously, you don't want to turn all your flyers into 1/1s for ... but I would make this happen more often than it does in normal Magic.

Whoops. Yeah, I mixed them up. If you have an empty set of creatures, they all have flying (and also neither does and some do and others don't).

But this is easily fixed. Noncreatures would say "As long as you control one or more creatures and they all have flying...".