Impure World Reincarnation was merely a manner of speaking.
The Impure World Reincarnation Uchiha Yue spoke of was certainly not the Second Hokage's Impure World Reincarnation, but the Death God's Impure World Reincarnation.
Having grasped two strands of the Death God's power, Uchiha Yue vaguely sensed that these two powers were the key to reviving his parents. Never mind whether those two strands of the Death God's power could cast Impure World Reincarnation and bring his parents back to life—given their importance to the Death God, as long as Uchiha Yue could become stronger than the Death God, he could make a deal with it.
But...
Why did a deal require strength?
Because without the power to suppress the other side, it would not be a deal, but a one-sided purchase.
If he could completely suppress the Death God, Uchiha Yue would have the ability to use the two masses of Death God power in his hands to revive his parents through the Death God. However, if he lacked the ability to suppress the Death God, then even if Uchiha Yue made a deal with it, his parents would likewise remain under the Death God's control.
That would mean Uchiha Yue himself would be constrained by the Death God.
That was not an outcome Uchiha Yue wanted to see.
Then, as he wandered aimlessly through the Land of Rice Fields, Uchiha Yue felt that everything had changed while listening to Orochimaru speak, while he alone had remained the same. Yet that feeling had been faint while he listened to Orochimaru. Only when he strolled through the streets of the Land of Rice Fields, watching the bustling roads and noisy crowds, did Uchiha Yue truly realize how out of place he felt in this world.
It was a loneliness that no