On the one hand, he he pun.
On the other, this is actually something I've been wondering about all season. It's obvious Wander helps people because he loves doing it, but Sylvia has a tendency to be put off by the inconvenience and often has to be convinced by Wander to help people.
So why is she so attached to him? Wander causes her a lot of inconvenience, and she isn't really drawn to others with Wander's personality type, so I doubt she was won over by his charm/cuteness.
The answer is that he challenges her in away no one does. Sylvia is competitive, rude, and adrenaline seeking. In most of her relationships we see, the other party tends to encorage those aspects of Sylvia's personality, and she is very easily swayed by their egging to slip back into old habits. Aggression and crass feel natural to Sylvia and seems to have brought her a lot of success in life.
Wander pushing her to be kind and patient was a completely new experience for her but, perhaps to her surprise, she found something worthwhile in it. Something worth pursuing despite how unnatural it felt.
It really means something to Sylvia that Wander believes in her enough to keep pushing her in a direction no one else would even think to encourage her going down. Wander presence isn't meant to "fix" Sylvia, in fact it's mostlt portrayed as a good thing that she retained a good chunk of her pre-Wander personality, he just pushes her be more than she'd ever considered she could be.
