Black Zetsu returned to Rain village and shuddered for a moment remembering his talk with Naruto. He knew there was no other way for him but to trust Naruto. Otherwise, all his plans would go haywire and If he didn't do anything, Naruto can collect all the tailed beasts himself easily as he's now the strongest person in this world. As Naruto offered his help with the payment of half of the chakra of tailed beast, he can use the other half to revive his mother. This was a bargain he could'nt refuse. Otherwise Naruto might take full.
Zetsu then entered the meeting room and spoke "Pain, I've secured a way to get seven tails, eight tails and Nine tails. Now you guys have to collect the four tails, five tails and six tails and our plan will work." Hearing this pain asked "What is the way you speak of?" Zetsu replied "I've made certain preparations by tricking the Ninetails Jinchuriki in collecting the tailed beasts and giving up his own tailed beasts. You just have to collect the three tailed beasts and the others will be brought by him". Pain nodded and said "we'll take care of collecting"
He then assigned missions for the Akatsuki members in the room. After everyone went out, a swirling portal appeared and out came Obito. He asked Zetsu "What happened? How did you trick the Jinchuriki?" Zetsu scoffed in his thoughts 'Who tricked who? I was lucky enough to make a deal with him'. He then looked at Obito and spoke "It was easy to trick him as he was betrayed by the village and due to Danzo's involvement. He believed in us creating peace by taking away the tailed beasts". Obito nodded and disappeared in a swirling portal.
The four tails and five tails were secured by Iwa while being sealed inside Roshi & Han. They were both also protected by Iwa. While the six tails was sealed inside Utakata who killed his own master and became a rogue Shinobi. So getting the six tails would be easy and akatsuki had to go on a full fledged battle with Iwa if they want to get the four tails and five tails. So they decided that Pain will go after Iwa and the team of Itachi and Kisame will go to capture Utakata the six tails Jinchuriki. Zetsu was the best tracker and he provided the locations of the tailed beasts easily.
The Akatsuki made its move. Pain and conan went close to Iwa and created a base of operations using Konan's paper jutsus. The base resembled a huge tree in the forest which was not distinguishable unless inspected closely. After they created the base, Konan stayed to protect Nagato while Nagato commanded the six bodies of pain to move towards Iwa. The Animal path entered the barrier of the village flying in the sky and summoned the other bodies. After that all six bodies of pain entered Iwa.
As soon as they entered, they were noticed by Iwa Shinobi and a lot of them arrived at the scene. As it was war, they were very alert and noticed immediately. Ohnoki also arrived almost immediately and seeing the six pains he frowned and asked "Who are you? What business do you have in Iwa?" The deva path pain which was Yahiko's body responded "We are the Akatsuki. Hand over the tailed beasts if you want your village to be safe." Ohnoki had visible anger showing on his face. He started to float and launched an attack on deva path without warning. The Shinobi also followed. "Particle style-Atomic dismantling jutsu" and many other ninjas also used various earth jutsus.
A square cube was formed in the hands of Ohnoki and covered the Deva path pain. Deva path seeing this, said "Shinra Tensei and a gravitational force sprung out destroying the particle style cube and blowing away all the other ninjutsus along with the Ninjas in the vicinity. Ohnoki was visibly shaken seeing the power of the intruder and then he witnessed the rinnegan eyes on all of them. Deva path pain spoke "Surrender the Jinchuriki or feel pain". Ohnoki got angry again and yelled "Never. The tailed beasts belong to Iwa. Get out and I'll spare your life.
The animal path appeared and yelled "Summoning Jutsu" and summoned a dog and bird creatures. The Iwa Shinobi attacked with everything they have, but the dog just split again and again into more dogs which attacked the ninjas without dying. Ohnoki used particle style on the dogs to destroy them, but was stopped by Petra path which absorbed the ninjutsu. The ninjas managed to beat one of the bodies of pain, but the Naraka path summoned a huge head and restored the beaten body of pain. The battle was going nowhere and the Jinchuriki Roshi and Han had to step in.
After the Jinchurikis Stepped in the fight, the fight went on the favour of Iwa which made Nagato angry and at the same time, all the bodies of pain dropped down but the Deva path. The deva path then started ascending to the sky and used "Super shinra tensei" and a very huge gravitational force erupted around him blasting off anything or anyone away from the deva path as the centre. Ohnoki yelled "Noooo" but was too late to stop it. The other shinobis also used various earth style ninjutsu to block the force but to no avail.
With the attack done, Half of Iwa was converted into a wasteland. This made Ohnoki shed tears. The deva path then clasped his hands and yelled "Chibaku Tensei" and a black ball formed and was launched from his hands. The black ball started attracting everything around it including the blown away Jinchurikis. As the Jinchurikis started floating into the black ball along with various land masses, Ohnoki started attacking the deva path in anger. Ohnoki became so mad that he lost his reasoning and continued to attack.