Not sure if this is intended, but I think there’s a relationship between three mechanics from the Theros block: Monstrosity, Tribute and Strive (and just a little with Devotion).
I don’t know if this is intentional, but seems to me like there’s a story embedded in the mechanics, which were switched between sets of the block:
At first there’s monsters roaming around. You have heroes to take them down, but they’re often just beyond the reach of a single hero, no matter how much you help them. (Monstrosity)
Then, the humans take a different approach. They begin to appease the monsters. Some of the monsters still remain a threat, but at least you can control it a little bit. (Tribute)
Lastly, the people take matters into their own hands. This also means forgetting the gods. (Strive, although we have only one example of this so far, and there aren’t any Devotion cards beyond the gods in Journey into Nyx according to MaRo)
I don’t know how many are going to be aware of this, especially since it doesn’t really show up in games, and the packs are drafted in reverse order, but I guess I picked up on this, there must be a small number of Vorthos-players who will too.
Of course, the mechanics are trying to explain the world in some way, but in this case the lack of a mechanic is also telling. So, as my new MtG-career is still pretty new, I went back and looked at previous blocks. Return to Ravnica doesn’t have this, because of the multitude of mechanics, they couldn’t bring any new in (they did have split cards and fuse, which apparently does have something to do with guilds finding allies) and because of the nature of the block, they couldn’t leave any out in the third set.
However, in Innistrad this is again very clear, perhaps even too clear. The first set has Flashback, Transform and Morbid (and actually fight, but I think we can also think of this as its debut as an evergreen keyword), the next set brought in Undying and Fateful Hour, while almost all those were dropped (only Undying survived, or bounced back) for the third set and instead Miracles and Soulbond appear.
So, at first there’s this general fatalistic attitude (and for a reason), but things get worse as the things that died don’t seem to remain dead anymore (Undying) and humanity is close to extinction (Fateful Hour).
But then Avacyn is restored and humans once again have the tools to fight back through teamwork (Soulbond) and just plain old outside help (Miracles). Undying remains, because black doesn’t get any Miracles or Soulbond cards.
Again, its not only the mechanics in the set, but also the mechanics that are gone from the set.