Itachi sensed the presence of a fourth person outside the field the moment they approached.
However, he did not take that person's presence to heart.
Aside from his younger brother being thrown back by Arata Uchiha again, disrupting his focus somewhat;
another reason was that he was certain that, given Arata's personality, he would want to settle their past grievances personally and would not readily borrow someone else's strength.
Moreover, before Arata used the transportation technique, he had already mentioned that someone had been waiting for a long time. Therefore, the fourth person who appeared here was most likely merely a witness.
As for who that person might be, he had already speculated while being transported.
After all, he had to admit that nearly ten years had changed the gap in strength between himself and Arata. The other's talent had already surpassed his own.
Therefore, every detail during the battle, every opening, was information he needed to gather and opportunities he needed to seize!!
Only then would he have time to stop Pain, save the village, and save his brother.
The only connection between the two of them was someone from the old Uchiha Clan, so the witness today was most likely Izumi Uchiha.
Taking her hostage during a break in the battle would be the best way to break the deadlock.
Yet when a voice from the past, buried deep within his memories, rang out beside his ears once more, his mental world began to crumble.
[That is...]
[How is that possible!]
[How can this be possible!!]
His disordered thoughts rippled through his sea of consciousness.
The suppressed statement, "What if I had not saved you back then," made his breathing stop for an instant. His flawless defense, built with utmost vigilance, suddenly revealed a crack because of it.