Not a lawyer, but I’ve had to deal with copyright before. If I’m not mistaken, the only thing the Smite devs could feasibly hold a copyright to is there specific expression of the characters - i.e. the unique visual design, the voice lines, the lore (assuming it’s not also just the lore from already existing public domain works), animations, etc., that’s the only time you’d be in trouble. With game mechanics it’s pretty dicey because I think you’d have a hard time finding a judge to actually rule that any company “owns” a game mechanic. But if you copy how the characters look, the art style, maybe even specific dialogue (which couldn’t be found as part of another public domain work) that’s when you could possibly have a claim.

But even still, you have to remember that copyright is not this “oh you’ve broken the law you’re a criminal now” type thing where once you’ve “infringed” it’s over. It’s typically handled first via informal means like contacting Steam/Epic/GOG/etc. and saying “hey we believe these guys have stolen our character.” They’ll have to convince the platforms first, and then the platforms will take it down to avoid liability. It’s only if the parties want to pursue it further will they have to take it to court and have a jury/judge rule on it. Copyright suits tend to be ruled on precedent rather than just the black-and-white letter of the law.