The gift to Naruto is...
The gift to Naruto could be a sealing technique. I particularly dont want it to be a sealing technique but I think it could be, why do I say this:
1. Itachi knows about seals, he sealed amaterasu in Sasuke. And the seal(crow) may be predetermined to activated with Itachi's eye. (Sasuke has Itachi's eyes now).
2. Itachi was with ANBU which I am assuming knows sealing techniques.
3. The only way I can think ( of right now) to bring Sasuke back to Konoha, without killing him, is if he loses his powers or eyes.
4. The crow seems to have a 4th tomoe. In the world of Naruto to seal an odd number you need an even number (or vice versa). So the 4 tomoes will seal the three tomoes.
As I said, I dont want to be a sealing technique but there is a possibility. I just want Naruto to beat the ... out of Sasuke and that's it.