Aizen, Light, Pain, and Char. These are 4 characters that one could say had a point in their motives or that their objectives were, or at least started off, noble. One would have to be very careful when they said it though and only under the right circumstances but they could still say that they were right.
Ren never thought he would ever admit to one of them being right. But here, Ren was saying to himself.
'Aizen was right.'
Ren decided that under the confusion of an invasion was the best time to eliminate other captains. This was not just for canon but also another more official reason. Soul Society had been getting more and more corrupt just as Aizen had said it had been doing. The difference is, Aizen could see the corruption with only a 300-year life while Ren had been around for twice that amount of time.
The Central 46 allowed captains and noble families to get away with many crimes with no punishment handed out to them. Ren even knew of 3 minor noble families and 3 captains who helped plan the invasion, he just did not know when it would occur.
His division's members had not been sitting around ideal all this time. The only group who had more intel of Soul Society was the Onmitsukido but theirs was limited to what the Central 46 and Gotei 13 allowed them to investigate.
The first place that Ren stopped was outside of the minor clan, the Naraki Clan, compound. He walked into the gates as he saw no guards until he approached the central courtyard. Inside, he saw the heads and the 3 minor noble families, the 3 captains, and the rest of the members of the three clans.
All were shocked to see Ren appear before them during this time. Anyone would have thought that he would have been busy defending his own division.
"Why, hello Captain Ren. What brings you here?" asked the current captain of the 5th division, Himoya Ken.
Ren lifted his bokken with his left hand and pointed it at the group. His right arm was still regenerating at the moment so he could only carry out his plans with a single arm.
'That should be enough of a handicap with me though.'
"3 captains are sitting here and drinking tea while Soul Society has been invaded. But this is not what you asked. You are asking me what I am doing here.
Well... I am here to kill 3 captains and wipe out 3 clans who helped our enemies invade us as well as abandon helping us to combat the invaders while they sit in their homes and hide."
Hearing that Ren was coming to battle them, the 3 captains decided that they should no longer play dumb. They had to go all our or risk being killed.
"Bankai!"
"Bankai."
"Bankai!"
The captains of the 5th, 12th, and 13th division used their bankai immediately. This was a battle where delaying it would mean their death. But before they could even finish their transformation, the captain of the 13th division was killed by a blow to the head.
'Why do people always wait for the transformation to end?'
Himoya and Jerald both were shocked to see their comrade die so fast. Among all the shinigami, Ren most likely had one of the fastest shunpo at the moment.
After a moment of their reiatsu being released, the duo revealed their bankai states. Jerald was in a large, jelly-like, humanoid armor. Himoya on the other hand had a bat'leth in his hands.
The duo charged toward Ren with Jerald taking point. The figure smashed down his fist toward Ren but the captain of the 8th division was able to block it with his sword.
Himoya appeared behind Ren and was about to strike at his head when he felt pain in both of his arms and legs. He looked down and saw 7 tree branches piercing through his limbs while another branch had just curled around his throat.
"Art is an explosion."
The tips of the branches detonated inside of Himoya while the one around his throat exploded as well. The former captain's body was blown to bits in a single move.
The clan members saw that 2 of the captains they were relying on had already died so they decided to try and leave. Once they looked outside of their compound, they saw a giant wall of branches. With this, they were unable to escape now.
The group was about to start launching attacks on the wall to try and break free but they then heard a voice behind them.
"No point. Just accept that you have lost this game and will have to play better next time."
They turned around and saw that Ren was carrying the bloodied haoris of 3 captains with one having several burn marks and another one being sliced in half. To them, this scene looked like the devil was carrying back his spoils from hunting.
"Please! Plea..." But Ren did not give them a chance to start begging. He summoned countless tree branches that pierced through and killed every member of the 3 clans. Ren walked around and collected the 3 clan zanpakuto that remained before feeding them to Dryae.
'How full are you?'
'Hmm. I can eat a few more. I'm not sure what we will get from eating these though.'
'Neither do I but we can worry about that later.'
With all the members dead, Ren summoned a forest of trees within the compound. The branches wrapped around all the buildings and covered the dead bodies of the people.
Using shunpo to escape from the gates, Ren pulled out a sheet of paper as he detonated the forest of trees. The entire compound was blown to bits with almost nothing remaining.
'Let's see. So we have these 6 already off the list. We need to deal with the 3rd as well if they are not already dead. The Central 46 could also use some restructuring. Gosh. I am such a humanitarian for doing all of this.'
Ren mentally pat himself on the back as he went towards his next destination to find his next target. He had to act fast before the invasion ended.