Moments before their first matchup at the 2018 Injustice 2 Pro Series Grand Finals last Tuesday night, Dominique "SonicFox" McLean made Curtis "Rewind" McCall a promise.

The year-long DC Comics fighting game circuit was down to its top four players, with SonicFox and Rewind battling to determine the winners bracket finalist. Regardless of the outcome, SonicFox wanted to make sure his Injustice sparring partner didn't leave the Chicago tournament empty-handed.

Something more important than a NetherRealm payout was at stake: Back home in Las Vegas, Rewind's 61-year-old father, Welton McCall, was battling stage 3 colon cancer.

"Before Top 4 even started, [SonicFox] was like, 'If I win, I'm willing to split a piece of my money for your father to help with treatment,'" Rewind said. "It was pretty surreal, and for Sonic to do that genuinely shows how good a person he is. He's one of my closest friends in the FGC, and in general he makes sure I'm taken care of. I know he's got my back."

SonicFox kept his promise. After sending Rewind to the losers bracket with a 3-2 reverse sweep in the winners finals, he again humbled the reigning Evo 2018 champion 3-1 in the grand finals, buoyed by an underrated Joker pick not even Rewind's canonical Batman could overcome. As he conducted the championship postgame interview, clad in the iconic blue fursona now synonymous with fighting game excellence, SonicFox pledged $10,000 of his $40,000 grand prize toward Welton McCall's medical expenses.

"[Rewind]'s a good friend of mine and I know what he's going through must suck," SonicFox told ESPN via email. "So I thought just being a good friend would help him a lot."

At only 20 years old, SonicFox is already the winningest fighting game player ever. The four-time Evo champion has amassed more than $525,000 in prize money across numerous games over his five-year career. Through all his success, SonicFox hasn't lost sight of the people who helped him get there, sometimes splitting the top prize or picking up the tab after hosting a large post-tournament dinner with several fellow competitors.

Event organizers might bristle at the thought of a thrown final, ruing the possible loss of competitive integrity, but SonicFox doesn't see it that way.

"I only do it with friends that make it to grand finals with me when I know we've trained hard to get there," SonicFox told ESPN via email. "Tournaments definitely think splitting is colluding, but it's not the same thing. I will put my all into a match always."

SonicFox's display of generosity in Chicago was not lost on Rewind, the 17-year-old who beat Sonic at Evo 2018 and helped train the legend back into form for Injustice 2.

"The donation meant a lot, especially to my dad," Rewind said. "He tuned in from his hospital bed to watch me play Sonic. He saw the announcement and called me, said he was really happy."

Welton has always been Rewind's biggest supporter, even when he was placing ninth in some faraway tournament. Riding out those early failures wasn't easy.

"I would get pretty down on myself, beat myself up," Rewind said. "I don't know if I even want to do this anymore, [it's] kind of a waste of time, and he would always be like, 'It's not going to come just like that, you have to keep at it, just keep working.'"

This year has been a roller coaster for Rewind. The high schooler's first significant professional success -- finishing third in Mortal Kombat XL at Combo Breaker last May -- was followed by his father's diagnosis just one month later. A colonoscopy revealed that Welton had been living with the disease for nearly a year, shocking his family and triggering a series of expensive medical procedures.

Now it was Rewind's turn to support his father. With Welton unable to work his job as a kitchen steward at Sam's Town Hotel, Rewind stepped up to help his mother pay the bills. The $1,300 he won from the Injustice 2 SoCal Regionals went directly to the medical fund, as did the $4,779 he raised from a successful GoFundMe campaign (whose $2,000 goal was met within three hours thanks to signal boosting from the fighting game community). But costly MRIs, CT scans, chemotherapy, radiation treatment and surgery continued to add up.

"Our radiation bill, even after insurance covered most of it, was still over $4,000," Rewind said. "And that's not even including what the surgery is costing, this was just treatment leading up to the surgery. I remember my dad showing me the bill and him being really disappointed, really shocked that it cost that much just to keep him going."

Rewind's recent string of high-profile esports finishes have helped blunt the financial impact of his father's medical expenses. The winnings from Evo and IPS Grand Finals (including SonicFox's donation) amount to nearly $40,000, which will likely be needed for the upcoming surgery bill. Welton went into surgery last week, just days before Rewind flew to compete in Chicago; he spent over a week recovering in a hospital bed before returning home Tuesday.

"I'm praying he's cancer-free, but you never know with this disease," Rewind said. "Seems like when you think it's gone, it comes back. It's a pesky bug to get rid of. People fight this for years, but all I can do is hope that it's gone and it's the last time we have to do these procedures."

It's a lot of troubling uncertainty to absorb for Rewind. He's already balancing life as a Sunrise Mountain High School upperclassman with his burgeoning esports career. And who knows what the future holds for the fighting games he's specialized in, with Injustice 2 and Mortal Kombat XL in states of transition.

But one thing has become clear: At its best, the fighting game community is capable of incredible acts of kindness. SonicFox is proof of that, a fighting game polymath who understands when to set aside the trash talk and use his powers for good.

"The community just loves itself," SonicFox said. "We have our rivalries, and our trash talk, but at the end of the day we are all playing video games. I definitely feel the FGC looks after its own."

Apart from SonicFox's gesture, numerous pros from other titles united behind Rewind and his father when they were in need, many without ever having met them before. Welton, who still brings a pager to work and whose son lovingly considers him "old school," remains stunned by connections formed over video games, facilitated by the internet. It's hard not to feel the love.

"He was surprised that people who didn't even know him would give up their hard-earned money to help keep him alive," Rewind said of his father. "A lot of people care. The fighting game community is like family to me, and my dad feels that the fighting game community is like family to him, too. It's amazing."