The young man is not a very good fighter, because he doesn't really like to make fight his Pokemons. He prefers to be seen as a trainer who likes to take care of his Pokemons and become their friends. He also captures very few Pokemons, with whom a connection will be created, but mostly, he preferres to leave them free in the wild. When he was little he wanted to become a Pokemon raiser, to take care of those who are abandoned or in need of rest and love.
Mimikyu: When he was a kid he wanted a Pikachu because it was a Pokemon who was fashionable. But, since it was also a common Pokemon, his parents wanted him to have another more rare or luxurious creature. Sad, Steve would often go for walks in the woods surrounding his house, especially when his parents were away for work and he was under the supervision of a nanny. It is during one of them that he will come across Mimikyu, who he will take for a Pikachu. Steve will be so happy to have found the Pokemon he was dreaming of, that he will start talking and sympathizing with this strange Pikachu. Mimikyu, happy to be loved and to have found a human who is not afraid of them, will let themself be captured. And even when Steve finds out that it is not a Pikachu but another Pokemon, he will continue to love his Mimikyu, who will have become one of his best friends.
Cinccino: It was originally a Minccino, that Steve received as a gift from his parents when he was a child. They were chosen because of their fur which is quite luxurious, and also because they are a neat freak. Steve and Mimikyu often quarreled and fought against Minccino/Cinccino, who attacked them when they returned from a walk into the woods or one of them (oftenly Steve) left dirty things lying around. Still, Steve likes his Pokemon very much, especially since when Steve was older and no longer needed a nanny, Cinccino would take care of the cleaning of the house and take care of Steve, when he was sick or sad/anxious. He knows that Cinccino is there for him and will take care of him, like himself, will be there for his Pokemon when something can happen to them.
Milotic: It was during a fishing trip, one summer, with his friend Tommy, that the two young boys caught a Feebas. Although it is Tommy who found the Pokemon, it is Steve who will capture them, due to the fact that Tommy found Feebas "too ugly and they look stupid". Steve, who also found this Pokemon weird, developed an affection for the creature, who reminded him a little of his friend Mimikyu. Also, what was his surprise when, by presenting his new Pokemon to his parents, they congratulated him on his find (it was one of the few times when his father was proud of him). They explained to their son that this Pokemon was extremely rare and that they can evolved into a Milotic, if Steve takes care of them and pampers them. Although it took a long time, Steve will manage to evolve Feebas into Milotic.
Whimsicott: This wild Pokemon was fluttering in the air when they entered the Harrington's house, whose windows were wide open. They will venture into the house, visiting the rooms one by one, while spilling cotton on their way. They will eventually be discovered by Cinccino, who angry at seeing so much dirt, will fight against the other Pokemon. Steve, who will be alerted by so much noise, will try to calm his Cinccino, who was chasing Whimsicott, causing more damage. It is ultimately Milotic which will calm everyone down, by watering them. Weighted down by the water that their cotton fur has absorbed, and unable to move, Whimsicott will let themself be captured by Steve. Sadly, Whimsicott and Cinccino would never get along, mostly because the first one finding it extremely funny to drive the second one crazy.
Lycanroc (Midday Form): Steve will meet a young Rockruff during his trip to Hawaii (with his parents). This Pokemon, typical of hot and sunny regions, will befriend Mimikyu and Cinccino, who didn't dare follow Steve and Milotic in their swim time, and were waiting on the beach. Upon their return, Steve and his Pokemon will also befriend the young Rockruff. At the end of the day, Steve will capture Rockruff, who didn't want to leave their new friends. Very quickly, the Pokemon evolved into Lycanroc (Midday Form), having become the keeper of the Harrington house, mostly watching over the property when Steve's parents are away.
Vanillite: This Pokemon was one of the creatures that belonged to the owner of the Scoop Ahoy store, where Steve worked in the summer of 1985. Much like Steve, Vanillite was new to work and was regularly mocked by the Vanillish and Vanilluxe who also worked at the shop. Curious and clumsy, they will secretly follow Steve, Robin, Dustin and Erica in their adventures against the Russians soldiers. After being discovered by the group, Steve will take care of them and order them to hide or follow Dustin and Erica to avoid being caught. When the mall is destroyed after the Mind Flayer attack, Steve will return Vanillite to their owner. But, when this one saw how Vanillite is attached to the young man, he will give him the Pokemon.
Steve rarely leaves his Pokemons locked in their Poke Balls. They are often free to wander into the house, as and when they want.
Mimikyu is the one who will give the idea of "King Steve": how to pretend he is a really cool guy, loved by everyone, envied by everyone, while, deeply inside, he is totally different, just a nice guy who deeply loves his Pokemons.
Also, Mimikyu often likes to hide in the dark corners of Steve's room. They are regularly joined by Whimsicott, with whom they will sleep, nestled in the cotton of the other Pokemon.
Whimsicott likes to play tricky tricks on Cinccino, leaving pieces of cotton in the house after the other has cleaned up. This has the cause of annoying Cinccino, who is a neat freak.
Milotic loved to swim in the pool and spend their days there. But following the disappearance of Barbarra, Steve will not let them swim there anymore, fearing to see his Pokemon caught and killed by a Demogorgon or another monster. So he will often go to Lovers Lake and leave Milotic swim there, as much as they want.
Cinccino loves to hug Vanillite, to refresh itself after its cleaning session.
Vanillite enjoys playing and training to master its ice attacks, with Milotic helping it with its water attacks.
Lycanroc (Midday Form) is one of the few Pokemons that Steve uses when he has to fight against another trainer.
Steve's mother has several cat-like Pokémon, such as two Persians (one of each form: Normal and Alola), Glameow, Purrloin or Delcatty for example. They don't get along very well with Steve's Pokemon.
The same thing is happening with Steve's father, who has more Pokemons often seen as expensive and rare, like Salazzle, Omastar, Kabutops, Aurorus or Pyroar.
