Michzai headcanons
Michi is 3 years older than Ozai. Azulon and Michi's parents planned for them to marry as Michi was the youngest noble candidate at the time Ozai was born.
Michi didn't understand the concept of marriage at the time, but was told to make a good impression. It was fairly easy given Ozai was a baby and naturally didn't register why she was there outside of being a playmate.
As Ozai grew, he once sneezed fire at her by accident. It was how his bending was discovered at age six.
When Ozai was about to turn ten, Azulon decided to officiate the wedding. Ozai didnt truly understand the purpose of the marriage, especially not why it was shoved onto his birthday, but Azulon promised he'd be allowed to consume more cake if he behaved and didn't stirr up trouble.
Iroh, who was married on his eighteenth birthday, did try to tell Azulon to at least wait until Ozai old enough to understand, but Azulon insisted since he figured Ozai would be less competent and wanted a headstart.
Michi did have a slightly better grasp of marriage, but her view of marriage is rather sheltered and has a fairy tale view of living a happily ever after and being a loving wife/mother.
Ozai and Michi had their first baby as teens, 14 and 17 respectively. The baby was born in winter and rather sick, but they tried to make the best of things.
Ozai and Michi weren't prepared to parent. The kid mostly spent time with the servants since Michi and Ozai weren't sure what to do with the kid a lot of the time, though Michi tried harder to replicate it.
Still when Ozai did have the kid around, he tried showing the kid his bending since obviously that was what Ozai took pride in. Ozai found the baby lacked spark and was disappointed but tried to at least not reject it since he figured the baby would grow out of it.
When the boy turned seven months, the baby died suddenly. Ozai and Michi were distraught, though Michi was mainly the one who was hysterical. Ozai was quiet and didn't understand what had gone wrong.
Regardless Azulon asked them to try having another baby. Insensitive but they still needed a heir so Ozai and Michi did it again only for a miscarriage to happen.
This cycle continues over the course of 12 years.Either the baby survived only to die later, was a stillborn or was a miscarriage. The marriage was basically just Ozai and Michi trying to have a kid only for it to not make it.
Eventually Michi, who was tired of being used as an incubator, wanted a divorce. Frankly Ozai wasn't against it either. They were both sick of this cycle of having children just for the kid to not make it in the end. This accumulation of events caused Ozai to be more bitter and cold and Michi to fall into a depressed state. Ozai's envy only got worse when Iroh had a single but healthy baby, Lu-Ten.
Azulon of course, tried to convince them otherwise but Ozai outright told him that they weren't having anymore children. Azulon knew he wouldn't get anywhere, especially frankly it was obvious that Michi and Ozai weren't compatible enough to raise a child that'd survive so he begrudgingly allowed the divorce and Ozai was given a small year break.
Azulon reached out to the sages and managed to find Ursa. Ozai was not pleased his father was trying to hook him up with someone, but begrudgingly gave in to his father's demands in hopes it'd be over soon enough.
The wedding went as expected, but Ozai didn't really look at Ursa. Even during the pregnancy, he barely stayed in the room with her. When Zuko was born, he was small and sick and Ozai already prepared himself for the worst.
Ursa tried to get Ozai to bond with the baby, but Ozai refused, not wanting to get attached. Only when Zuko made it past seven months did Ozai appear to look at him, as Zuko had survived longer than the other babies.
When Zuko proved to survive, Ozai did begrudgingly try to parent and act like a husband rather than just coldly rebuking Ursa. Still, it took a lot of talks from Iroh before Ozai held the kid.
By the time Azula came around, Ozai seemed to somewhat move past this...issue. Still he remained uneasy until Azula made it past seven months, but did at least participate a bit more.
Michi managed to have Mai with relative easy. It took some time for her to get over the losses, but she did enjoy having one successful baby in comparison to the conga of misery she had dealt with.