So, for example, let's say I chose Tempest and Lorwyn. I might make a card in Exodus with buyback that puts a +1/+1 counter on all creatures that share a creature type, then make a card for Lorwyn that could block creatures with Shadow, but didn't include the word Shadow, specifically.

It's probably worth mentioning that there was a time when Wizards didn't plan out their blocks in advance... Every block pre-Kamigawa was done in isolation from the other blocks around it. This all changed when Wizards dropped the ball between Odyssey and Onslaught block. R&D didn't know that Onslaught would be a tribal block... they just kind of stumbled upon it. But Odyssey was full of odd creature types... dwarves, cephalid and nantuko to name three. But Onslaught was also a continuation of the story from Odyssey... the end result was a very messy "Oh... all these Goblins and Elves just sort of showed up" response.

The good news is, this started Wizards on the path of thinking five sets ahead at all times, which has lent to a greater sense of cohesion in the game. Cards now aren't designed in a vacuum, but with an understanding of what is needed for this set, this block, and the block before and after it. But what if the blocks were unmoored from their respective years, and rehitched themselves to other blocks?

Ah, it's been 5 days. I fear Challenge 72 may have been too much of a thinker. I've been noticing my challenges have been going too far into the philosophical as of lately, and this one seemed to go one step beyond.

Next time I post a challenge, I'll make sure to throw a nice softball over the plate, to balance things out some. I'm writing this comment to bump the post to the top of the queue, for now.

It's a shame, I thought this was really interesting, but there weren't any blocks I thought I knew well enough to be confident making a card specifically for.

I'll wait till after Easter before posting #73 in case a few of us suddenly come up with some ideas at the last minute.

Mmm, I've been thinking "Ok; uh, The Dark plus... um, Mirrodin? Uh; how about fallen empires plus... maybe not. Wut?" and basically stumped completely.

I keep thinking of blocks that pair too well together, like Kamigawa plus Innistrad (which had a Spirit tribal theme), or Mirrodin plus Alara (Esper's artifact theme). It's hard to find the right level of disconnect.

Mm. Seems that way. My recent article hadn't given me much time to really parse this one out myself. I planned to hit complete my own challenge tomorrow. I really wanted to make this installment of "According to Gatherer" a one-parter, but that just isn't happening. It kind of got away from me.

I keep wanting to take some time to think of something for this, but I've been so very busy this week.

Got there. Slammed Mirrodin Block against Scars of Mirrodin block and ended up with Caustic Vein and Simple Rector.

I made Gilt-Leaf Oracle and That Which Masks.

Finally figured something out: Spirit of the Dragon. I'm not a fan of the implementation, but I wanted to use "13 minus CMC" to reward high-cost cards.

Created Spectral Precursor.

­Gold Sliver and Interrupt: Time Spiral meets Return to Ravnica.