This is a question for the Ridley fiends, the K. Rool bois, the Banjo fans, and the Steve mains; How have you dealt with ridicule, mockery, and bottom-line torment from other people who doubted you?
I found that the best method was to only respond when you had a feeling that the person actually wasn't in it just to hate on your character or to rub it in. Over the years the difference between how trolls approached you compared to people who wanted a genuine discussion became extremely obvious, it's just a shame that the haters outnumbered the genuinely curious outsiders 10 to 1. It's always best to not respond aggressively either, having a bit of tact helped the fanbase as a whole, 99% of the time when our thread got closed it was because a fellow supporter lost their cool with a troll. Other than that you eventually just develop a thick skin, it's like being a sports fan, you just have to accept that there are always going to be a lot of people who hate your team for various reasons and not take it personally.
For me the toughest years to support Ridley were from 2014 - 2016, Sakurai's interview where he took the side of "Ridley is too big" seemed to sway a lot of people who were neutral on the matter into becoming haters. Sakurai has earned every bit of respect he gets, but there's a not-insignificant part of the Smash fanbase that worship him to the point where they're willing to attack people who disagree with him. As a Ridley fan I very much felt like an outcast during this time, talk about the character was banned here on Smashboards outside of an enclosed group (and for good reason I must admit), the Smash subreddit could be very nasty against Ridley fans (they're particularly guilty of deifying Sakurai), and I even talked with quite a few fellow Metroid fans who told me to support Sylux instead. I can't speak for everyone, but for me it was impossible to not want Ridley in Smash, so I just chose to distance myself from a community that clearly didn't want me to be part of it.
This is very much a humble brag, but I think one of the most important parts of how to deal with the haters is to not gloat once you get what you want. If showing up the haters becomes a priority, you've lost sight of why you even started supporting the character to begin with. Just celebrate and move on.