Who would be the main villain in 'batman meets the shadow fanfiction'?

Perhaps the Green Goblin could be the villain. He's a classic Spiderman foe and could pose a real threat to both Spiderman and the Shadow.

Lex Luthor would be a great choice. He could be causing trouble in Gotham as well as Metropolis. His intelligence and resources would pose a significant threat to both Supergirl and Batman. He might be trying to manipulate events to make the two heroes fight each other so he can carry out his evil plans.

Maybe a corrupt businessman who discovers some ancient technology from the Old West that gives him superhuman abilities. He wants to use these abilities to take over Gotham and expand his business empire at any cost. He sees Batman as a threat to his plans and when the Lone Ranger shows up, he tries to get rid of them both. His greed and new - found powers make him a formidable foe for the two heroes.

Lex Luthor would be a great choice. He's Superman's long - time nemesis. He could form an alliance with some of Batman's foes like the Joker. Luthor could use his intelligence and resources to create a plan that only Superman and Batman together could stop.

Lex Luthor would be a great villain. He could be plotting to destroy Superman once and for all while also trying to outsmart Batman. His intelligence and resources make him a formidable foe for both heroes.

Maybe the Riddler. He could set up a series of elaborate riddles that not only challenge Batman but also the curious kid OC. The kid's fresh perspective might actually help Batman solve the riddles faster and catch the Riddler before he executes his grand plan.

Ra's al Ghul could be a great choice. He might see the daughter as a potential heir or a threat to his plans for Gotham. He could try to manipulate her or use her against Batman. This would force Batman to not only protect his daughter but also try to make her understand the true nature of Ra's al Ghul.

Dr. Eggman could be a great main villain. He might have a new plan that involves both the power of Sonic Underground's music and the Chaos Emeralds that Shadow guards. He could try to create a device that amplifies negative emotions through music and uses the Chaos Emeralds' power to spread chaos everywhere.

Trigon, Raven's father, could also be the main villain. He might see Superman as a new obstacle in his path to spreading chaos and destruction. His demonic powers would be a huge challenge for both Raven, who has a complex relationship with him, and Superman, who has never faced such a dark and powerful entity from another dimension.

Perhaps an interdimensional villain. This villain could be causing disruptions in both The Flash's and Supergirl's dimensions, forcing them to meet and join forces to stop it. The villain could have powers that are a challenge for both of their unique abilities.