Please bear with my english I'll try to make it short by stating mangafacts;
1-Sharingan is based on spiritual power,the stronger your spiritual power the powerful your eyes
2-Kamui is a dimensionnal transfer technique,the afterlife being just another dimension only restricted to spirits I...
Right now Sasuke is at the edge of revival of his clan,all he needs to do is to take Obito's eyes,gives his own MS to Sakura warps back to Naruto gifts him the other eye so that way for one Kaguya won't be able to separate them anymore and two he'll have his BF help him revive the Uchiha.
IMO...
Now that Sakura is gassed and Obito out of condition the only way I think for Sasuke to return back is ti switch his right eye with obito's MS and maybe give his right eye and obito's other eye to Sakura.So once they make it back naruto can make that state permanent for sakura and replenish her...
IMO this is it right,the perfect chance to develop Hyuuga story by having them being immune to IT,Kishi you have wanked enough Uchiha give Hyuuga also time to shine damn it.If I were your editor I'd have bash u