Since I was talking about creatures cheating fortifications, and the types of cards they may disallow us to make, I figured I'd make an example card. This one seems about right, and shouldn't screw up playtesting commons too much, since it is only as powerful as the commons it can search for.

You don't need "through." But yeah, it's definitely a "wow" card to first see, until you look at the costs.

So this is Planar Portal but more expensive and slower to get started?

Well, yes. But it also activates for . And can be activated on the turn after you play it, if you have access to . If you think that Planar Portal is fair, than I couldn't imagine this costing less. The Fortify cost could probably come down a peg, though, to let people play something on round two.

People complained about Planar Portal being too slow (although I wasn't one of them). In particular, they complained at the need to invest before getting anything back. This has that problem but worse: investing over 2 turns to get a Diabolic Tutor is rather unattractive, even if you are getting a tutor every turn from then on. It's just too front-loaded.

Perhaps you could take the Bringer of the Black Dawn approach, and drive the costs down by putting the searched-for card on top of the library. That'd turn it into something a bit like Archmage Ascension (get a free tutor each turn).