You can read Naruto 621 at this online manga site. Here is the summary of Naruto chapter 621: With the Tailed Beast Ball held by Hashirama Senju's humanoid creation collides with Madara Uchiha's Susanoo Sword it explodes. As the smoke clears, a Susanoo-clad Nine-Tails is revealed ready to attack Hashirama as he emerged from his wooden defence. With Hashirama praising Madara, he quickly grabs the ethereal sword and counters with several additional hands emerging from the ground to suppress the beast only for the tailed beast to destroy with a swing from another blade. Not wanting the landscape of the current area to be completely decimated, Hashirama quickly retreats to the coastline prompting Madara to give chase. As the Uchiha charged another Tailed Beast Ball onto Susanoo's sword and throws it, Hashirama summons a set of barriers which were enough to redirect the attack. Hashirama then attempts to reason with his friend and comrade, wanting to stop the battle but Madara noted that he was too far gone. Knowing that Madara was beyond the point of being persuaded, Hashirama enters Sage Mode and uses the gigantic wooden construct with which he prepares to attack. As the battle progresses, Hashirama remembers the first time when he and Madara met, skipping stones by a river. When asked who he was, Hashirama noted that he was currently Madara's rival in stone skipping, at which he was winning.