There’s kind of a lot going on here! Mistcutter Hydra has an X in its mana cost, has protection from blue, and it can’t be countered. How does Plasm Capture interact with that?
Well, the first thing to remember is that “can’t be countered” doesn’t mean “can’t be targeted by counterspells.” It just means any instruction to counter the spell will be ignored as an impossible action.
The other thing is that “protection” is an ability that only works while the creature is on the battlefield. On the stack, the Hydra can still be targeted by blue spells.
Next, let’s review Plasm Capture. It tries to counter the spell, then it sets up the delayed trigger to add some mana later. The second part of that doesn’t say anything about “if the spell is countered this way,” so that means it doesn’t really care if it was actually countered or not. It will still set up that delayed trigger regardless.
But how much mana will it add? Well, when a card has X in its mana cost, most people know that it’s treated like 0 most of the time. However, there’s a big exception for spells on the stack. When Mistcutter Hydra is on the stack, X is whatever the caster chose for X, and will count towards the converted mana cost of the spell. If I pay 4G for the Hydra, then the converted mana cost will be 5.
So let’s walk through a quick example to make sure everything is clear. My opponent casts Mistcutter Hydra, paying 7 for X (total cost 7G). I respond by casting Plasm Capture targeting it. Plasm Capture resolves, failing to counter the spell, but setting up a delayed trigger to add 8 mana of any combination of colors to my mana pool on my next precombat main phase. (I don’t have to choose the colors until the trigger actually resolves, by the way.) Of course, then a giant hydra resolves and attacks me…
So there you have it! Casting counterspells against uncounterable spells is rarely beneficial, but in certain cases, it might just be worth it!
Today’s Rules Tip written by Josh Stansfield
(suggestion from reader Christopher Pottorf)