Elliot, Jelly ©
Y'know, their marriage is canon thanks to me and xVerdelet.
Nikolai and Kava, if the war were to end in their lifetimes, would stick together after leaving the army.
Nikolai's hair grew longer. He'd open up a child daycare, because he likes kids.
And, next to his daycare, would be Kava's offices: a pokémon laboratory. He also offers hospital services for pokémon. He often makes trips next door to Nikolai's daycare in order to socialize the pokémon he raises and let the children get a chance to interact with pokémon.
They'd have a house in the space between the two buildings. OuO
Also, Kava cut his hair on the right side of his face, but he copied Nikolai's side-hair style. But... he doesn't know how to braid it, and he can never get it right when Nikolai teaches him. xD
And... they... got...
The boy, Elliot, was named by Nikolai. He's a bit of a crybaby and is constantly being teased by his twin sister, who's actually about five minutes younger than him. Timid and afraid to try new things, he's also scared of bugs, thanks to his witnessing Kava's overreaction to one.
The girl, Jelly, was named by Kava. An all-around daddy's girl, her favourite colour is red but she loves swimming and helping out with Papa Kava's work. She's daring, brave... but not very nice to her brother. She's actually very nice, though, and does lots of things for Elliot, like helping him with homework or giving him the bigger ice cream scoop. Despite being younger(though not by a lot), she acts as an older sister figure to the bashful Elliot.
When she grows up, she's gonna break a lot of hearts. She's going to be a dramatic beauty queen for sure; popular, good at sports, smart.
Btw, neither of them have blue hair because Nikolai's natural hair colour is brown.
Both of them have hair that grows brown at its roots, and seems to fade into bleached blonde as it grows out, like Kava's.