Well, one possibility is that Bakugou is initially frustrated with the hero society in the fanfic. Maybe he feels overlooked or misunderstood. The League of Villains could approach him, promising a place where he can use his power more freely without the restrictions of the hero rules. And he might be tempted by their offer, leading to his joining.
It could be the classic villains from the original series like All For One. He might be interested in baby Deku's potential quirk. Another could be Shigaraki, who might see baby Deku as either a threat or an opportunity to disrupt the hero world in a new way.
His aggression might become more unhinged. Without the moral compass of the hero side, he could be more willing to use excessive force. He'd still be competitive, but now it would be against heroes instead of his fellow hero trainees.
One likely villain could be Loki. He's always up to no good and loves to play mind games, so a card game would be right up his alley. He might be the one who lures Tony into the game.
One interesting concept could be the idea of baby Deku having unique interactions with villains. Maybe the villains are unexpectedly protective of him, which is a contrast to their usual evil nature. It could also explore how baby Deku's innocence affects the villains' plans or makes them question their actions.
It could be a variety of villains. Maybe some of the traditional Naruto villains like Orochimaru or Pain could be in the story and Naruto kills them. Or perhaps in this fanfiction crossover, there are new villains created that are a combination of Naruto - style threats and Justice League - type menaces. It's hard to say exactly without reading the fanfiction, but it would be interesting if it included some well - known Naruto baddies being taken out by Naruto in a new setting with the Justice League around.
In the 'Tony joins villains card game' fanfiction, Tony's presence could completely change the dynamic of the game. Since he is a character with his own moral code, he might try to reform some of the villains through the card game. For example, he could use the game as a platform to teach them about fairness and cooperation. This would create an interesting conflict as the villains are not used to such concepts. Also, his skills and intelligence would likely give him an edge in the game, but the villains may try to undercut him using their underhanded methods. It could be a really exciting story with lots of twists and turns as Tony navigates this new and dangerous world of the villains' card game.
In this fanfiction, it could be that Tony has a hidden agenda when he joins the villains' card game. He might be trying to infiltrate the villains' group from the inside. So he plays along with their card game, making alliances and enemies within the group as he goes. All the while, he's secretly gathering information to take them down.
In fanfiction, Shazam joining the Justice League could open up a world of new storylines. His relationship with other members could be explored. He might have friendly rivalries with some, like Green Lantern. His magic - based powers could also introduce a new element to the League's fight against threats that are more magically inclined, such as dark sorcerers or demons.