
A dumb silver-border design based on one of my favorite jokes. I tried to make it playable with a general triangle theme instead of making players square root numbers, though the joke becomes a little thinner.

Holding up mana for Cancel (and other counterspells) during an opponent's turn is stressful. You more or less commit to countering whatever they cast, and hope they don't figure out your plan. So a counterspell enchantment that you can cast in advance and use on demand is appealing. In fact it's too appealing. It shuts down interaction and creates frustrating play patterns-- at least, I assume that's we've never seen one (unless you count Common Courtesy). But maybe there's a similar effect that could work.
Pacifism is an iconic way for white to "remove" creatures by keeping them out of combat. Many powerful creatures these days can just shrug it off, though. Kenrith, the Returned King doesn't have to attack or block to make an impact. To counter this, recently we've seen more variants like Arrest and Trapped in the Tower that turn off activated abilities as well. But then what can we do about creatures like God-Eternal Oketra and Niv-Mizzet, Parun?
Rituals (spells that generate more mana than they cost) are tricky to design. Aggressive decks getting to trade cards for tempo is a cool idea, but almost any ritual that's good at that is even better at powering broken strategies. (Storm decks are the best-known example.) On the other side of the power scale, weak or restricted ritual effects aren't consistently good enough to be worth a card in most decks. If only we could print a ritual effect that didn't take up an entire card...
Reanimation spells like Cauldron's Gift usually have to target expensive creatures to be worth it. If you're spending 4-5 mana and a card, you want to be getting a creature that's worth at least that much, not some random 3/3. Even creatures with reanimation built-in often want extra bonuses when they come back-- like Pharika's Spawn and the other Escape creatures from Theros Beyond Death. So what would it take to make a 1-mana creature an appealing reanimation target?
Riot just released the beta for the League of Legends CCG, Legends of Runeterra. I thought I'd share my reactions: