The skeleton has a hard counterspell slot here, which has to be at least 3 mana and will often be 4 or 5. However blue common has a lot of four-mana spells at the moment: Misinform, Geass of Desertion, and the current set of stats for Unethical Researchers. So this might want to be just 3 mana.

There have been a couple of cards that are strictly better than Cancel recently, such as Neutralize and Wizard's Retort, so I'm hoping this is okay. It's clearly worse than Dismiss.

I'm on the fence about the "up to one" here. I was thinking I'd like it if you could use this without a spell to target, as a really bad way to trigger the draw-second-card rewards. But it's such a bad thing to do I'm not sure if the extra fiddly wording is worth it.