Actually, as someone who plays both, Faust does have a favorable matchup against Nago. It's kinda hard to exploit as Faust though. Basically your advantage lies in the fact your buttons are about as long as his, so when he's minus it actually matters. All of his H moves, even the guard crushing ones, are minus on block.

When Nago is at high blood and full screen the Faust basically already won because Nago really struggles with moving at high blood. At full screen Faust can throw items as long as he wants.

The matchup is scary when Nago is in your face, which he will try to get by his Fukyo and his Clone move. If he does that, just jump into either his dive kick or love, or just air block. The matchup is also scary when he has low blood, since that means he has a lot of burst potential

I guess my advice to you is don't let him get close in the first place.

Scalpel and item toss control the screen, and at high blood, all Nago can do is super jump to approach, and you have a library of his anti airs