Robbie being unintentionally good at dealing with the children’s flaws.
Stingy claims everything as his? Robbie figures he’d never had something that was truly his and helps him make his own clothes. That are his only, have only ever been his and were made specifically for him.
Trixie causes trouble left and right? She needs attention, she is bored. So he entertains her and puts her in charge of something so she can feel important.
Ziggy is obsessed with sweets? Let him eat all the candy he wants. After a day of stomach pain and nausea he’ll never want so much candy again. Some things you have to experience to know they’re not good for you.
Pixel doesn’t like social interactions and sometimes spends hours playing video games right until the next morning? Robbie teaches him ways how to cope with being an introvert and feeling overwhelmed by sensations and explains things to the other children so they can be considerate. As for the gaming, the power goes out suspiciously often lately…
And what about Stephanie? Well, sometimes she can be a bit forceful and stubborn and can’t see other people’s side of the argument. So Robbie, simply by telling her no and annoyedly pointing out the things she missed/ignored, helps her be less narrow-minded.
And he does all of that unintentionally. He just does it without second thought, as if that’s normal and obvious while Sportacus stands flabbergasted and very much in love.