Seeing a pregnant Hex Maniac brought to my mind a sad/heartwarming scenario. Maybe don’t read the spoilers
You meet a Hex Maniac in a graveyard. In some dark woods with lots of Phantump.
In this graveyard, you can read the names on the stones. She’s standing in from of a particular grave.
You get a little cutscene. She seems to be talking to herself and mentions a name, let’s say [yuuta]. She speaks to this inviolate [yuuta] in a very loving, caring voice. Before she fights you, she says [yuuta] is standing right behind you, and wants to play with you.
She uses Pokémon like Cubone, drifblim, Yamask, etc.
The Ace is a Phantump. After the fight, she thanks you, and urges [yuuta] to thank you. The phantump appears, revealing that’s she’s been talking to it the whole time. She says [yuuta]likes coming here on this day every year.
She then sees that [Yuuta] has taken a liking to you, and says he wants to go on a journey with you. She sees you’re a kind trainer so she trusts you. Once you trade, Phantump evolves into a trevanant. You can see that the Trevenant is named [Yuuta]. She asks you to take good care of it, and that she’s very happy.
Before that, in a nearby town there’s a rather sullen man, in a small house with a few ghost type Pokémon. He says that he used to hate ghost types but his wife was always obsessed with them.
If you come back to that man after getting the Trevenant he gets more dialogue.
He reveals that he used to have a child but he lost the child several years ago. He then understood why his wife was so obsessed with ghost Pokémon. It helps people get in touch with the other side. He says that even though he was devastated, his wife never stopped smiling, saying that through ghost Pokémon, she knows [Yuuta] is happy on the other side, and he’s always there, watching over them.
He then asks to see [Yuuta] the Trevenant and will give you a reward, saying it was his child’s favorite toy. Something like a Spell Tag.
The Hex Maniac from earlier will be in the graveyard. You can rematch her.
She says she has a husband and a son. Her son really loved going on adventures. One day, the son got lost in the woods for a long time, but eventually she found him again. She will regularly ask to see [Yuuta]. Maybe give you a reward if you have high friendship
She will no longer be standing in front of that grave, so you can check it. The name on the stone is [Yuuta]