>>29918815UBs are Pokémon like entities from another dimension. Lusamines husband was studying them, but then vanished into one of the wormholes to said dimension (turns out he is fine and just retired to the tropics, but no one knew this). Lusamine ended up becoming obsessed with the Ultra Beasts after this, to the point to where she modeled her own look, and her daughters look after ultra beasts.
Lusamine actually ends up summoning UB-01, which it turns out is a parasitic organism that is extremely poisonous and extremely addictive, making her obsession that much worse, and she rips open multiple holes into Ultra Space, which is where the rest of them start pouring through into the game.
