This seems really strong, especially given it's ub hybrid. It's at least a two-car combo, but you can pretty much run any color in either black or blue.

There are drawbacks in that the card does nothing but give you a non-cantrip Peek if you cant cast any spells in that player's hand. In that way it can sometimes be a worse choice than Duress or even Pain. But I got to agree that this can be a monster. At the very least, it makes a better counterspell for your opponents cheap spells when playing Draw-Go. Got a Dual Shot stuck in your hand? Don't mind if I do!

I would think that restricting this card to just Instants or Sorceries would keep things under control. That way you're either playing risky, playing other cards that let you see your opponent's hand, or sideboarding against a deck full of instants/sorceries. "Backbreaking, but only in the right scenarios" sounds good to me, power-level-wise.

I totally get why a person wouldn't want to design towards a niche, though. So let's presume the text isn't changing. Then I'd say this card needs to costs at least . As it stands, I have a hard time coming to grips with this card being easier to cast than Twincast... but I get how Twincast can double your own stuff and this can't.

Given the comments, I made it so that this no longer fixes for color. Now you can still use it on yourself to cast something as an instant, but with the drawback of revealing your hand. It's also significantly less likely you'll be able to cast an opponent's card, though.