Before working at Wizards of the Coast, I liked to imagine that mass-destruction spells like Armageddon and Wrath of God were designed by wide-eyed members of R&D who made explosion noises with their mouths while ramming toy cards together and stomping on that cool Lego house you totally thought was awesome.
Since starting here, I've learned that's not true. Mostly.
But to find out what developers were actually thinking when developing cards that explode all the things, I traveled through the Multiverse searching for comments on many of the game's most annihilating cards—starting with From the Vault: Annihilation's namesake.
Decree of Annihilation
Why, yes it is a super cycle.
Okay, so many of the cards in Annihilation are old enough that Multiverse comments are a bit slim. Still, several cards did have some interesting commentary to go along with their development.
WJ: Constructed card.
WJ: Ba-roken in testing—wacky rainbow deck with Lotus Vale, Necro, Man-o'-War
1.36 Changed from 1WW to 2WW
1.36 Power card for marketing (Tier 2)
Cataclysm ended up being one of the most powerful cards in Exodus, even with the increased cost. It was probably a bit better than tier 2, as Matt Linde used four copies in his White Weenie deck to win US Nationals back in 1998. Empyrial Armor on one of Linde's two-drops followed by Cataclysm was usually game over back then.
Child of Alara
Del 5/6: Confirm mandatory?
MT 5/7: Yes.
Del 5/28: Legend rule + leaves play ability could be interesting.
The mandatory bit was in reference to making it a "may" ability, which they clearly opted against. Making this legendary meant that playing two copies would make the world explode.
AF 5/19: Was sorcery.
AF 7/16: This card will likely change.
AF 8/17: New data gives this card a second chance (I guess it secretly has persist *rimshot*). Could cost 2HHH if we want to make it more attractive in light of white choose-2, although it already has visible upside.
Del 10/10: 4HH -> 2HHH.
Persist was one of the mechanics in that set. Aaron Forsythe, ladies and gentlemen! Note that the cost was changed to differentiate it from Austere Command. As a result, Fracturing Gust has become one of the premier ways to punish artifact-based decks like Affinity.
MT 7/8: Now Rare, and better worded.
KEN 7/21/2008: Doubling Season-matters!
Del 7/25: Doubling Season no longer matters. Sync'ed up with the others.
Doubling Season kind of still matters, but originally the number of tokens, rather than the value of X, was what triggered the destruction of all other creatures. The actual wording lined up with the other spells of this nature and made Doubling Season matter a bit less.
DH 3/30: And back to just W after more testing. Expect this to change back and forth. Eager for feedback on this.
DG 4/11: I still enjoy a Wrath miracle, I have no specific preference on its hosing of graveyard strategies.
DH 4/11: 3WW->4WW
MJ 5/24: Miracle cost of W seems too splashable for such a dramatic effect
Terminus ended up being a card in a pretty sweet spot—good enough for Standard but not format warping, but also different enough that it made an impact on Legacy. Seems like the developers got the costs just about right.
Day of Judgment
MR 1/14/09: Four mana mass creature removal in white—can we do this?
KEN 1/14/2009: Mossbridge Troll goes RAWR!!
TML 1/16/2009: hehe @ MR
Mark Rosewater, ladies and gentlemen!
AF 7/25: New.
DAL 7/25: I like this design and cost. Adds more main deck disenchants, and stops wrath players from hiding behind their enchantments, artifacts, and Planeswalkers while they wrath people. I like the three W's too.
KEN 7/30/2008: Yay!
AJ 7/28: This is great. Also, KEN seems to be time-travelling.
ND 7/28: For a card that destroys creatures, this card is decidedly pro-creature. I like.
Besides Ken's trip through time, there's some pretty fantastic soothsaying going on in here, as some of the comments portend Ivan Floch's victory at Pro Tour Magic 2015, where he definitely did not hide behind any enchantments or artifacts, and only a few Planeswalkers.