I believe I have a timeline for Chaos & Control that slots itself surprisingly well within the lore (especially for it being quite a retcon):
1933 - Oddfellow kills Jack during the Twisted Origins massacre, his blood getting on Jack thus accidentally giving him immortality and the powers of the Zodiac, as Jack's soul is then trapped in the Zodiac realm (not calling it the Oddverse), where Oddfellow tortures him for the next almost 50 years.
1980 - Jack's box is sent off and opened by the news crew, freeing his body and accidentally setting his soul free from the Zodiac realm, Jack is now running around as the immortal clown, Oddfellow gets scared as now for the first time ever, he's not in control.
2007 - Jack finds Oddfellow, kills him and steals the Cane of Souls, stuffs Oddfellow's body into the box and his soul into the Zodiac realm, the Carnival of Carnage ends with Jack forced to retreat back into the box, now it's his turn to torture Oddfellow (however, Oddfellow takes this time to also begin conquering the Zodiac divinities to fully master his power).
2010 - HHN 20 events happen, Jack is revealed to be a Herald, Oddfellow realizes this goes far beyond Jack sharing the Zodiac powers, he's quite literally Chaos incarnate and serves the God of Fear.
2010-2015 - It's now less one of them torturing the other, it's just turned into all-out war inside the Zodiac realm until Mary breaks the Lantern and sets the Heralds free, yet Oddfellow remains trapped.
2016-2021 - With Chance incarcerated and Jack back in the box, the endless battle continues, the playing field becoming more even as both ringleaders master their powers.
2021 - Adaru pulls Jack back into the Lantern and forces Oddfellow's body free from the box, allowing his soul to finally return to the mortal world, where he's now essentially a full God with complete mastery over the Zodiac. However, he's aware of the threat Jack poses and whether this was always his plan or, I like to think, now possibly out of pure spite and hatred for Jack, begins plotting to conquer fear itself and overthrow Adaru to cement himself as the most powerful being in all of creation.
2023 - The events of HHN 32 happen, Oddfellow hosts a new carnival of horror, collecting souls and harvesting enough power to challenge Adaru's hold on the Lantern.
2026 - With the 35th anniversary of HHN approaching, Oddfellow manages to crack open the Lantern and free Jack, offering his proposal of an uneasy alliance, with promises of standing alongside him as the most powerful beings in existence and no longer being held back as just a Herald of Fear, instead become a God, to which Jack accepts. Of course, both parties intend on betraying the other when the time is right, and are just as aware that the other plans on doing so as well, but that'll have to wait. For now, let the Infernal Carnival of Nightmares begin!