To perform this technique, the user must first acquire some of the DNA of the person they intend to revive. Kabuto remarks that this basically amounts to grave-robbing, although blood stains or organs salvaged after the target's death also work. The soul of the intended revived must also reside in the pure world (浄土, jōdo); those whose soul has been consumed by the Death God, for example, cannot be resurrected.
Torune being revived with Fū as the sacrifice.
Next, a living sacrifice is required for the soul of the resurrected to use as a vessel. Once all prerequisites for the technique have been met, the acquired DNA of the person is smeared on a special scroll and once the scroll is activated, the remains spread out in the form of a special seal with the living sacrifice in the centre. Then dust and ash encase the sacrifice's body, giving them the same appearance that the revived had at the time of their death. The process is apparently somewhat painful as seen when Fū was used to revive Torune. The person is then revived and the end product is usually stored in a casket until summoned by the user. The user can theoretically revive a limitless number of people in this way, so long as they have enough sacrifices, chakra and DNA to perform the technique.
does tobirama meets these requirements...is he gna meet these requiments just at that time??...its a long strugle....and it need time to revive asweell...what if she doesnt even gives tobirama any tym at all so how do u suppose its gna happen??