LOL I'm not asking all villains to somehow team up, it's not impossible but highly unlikely. it's just weird they suddenly disappear when superheroes teams up and fight a "bigger" villain then reappear in solo movies. for the heroes, after teaming up (in an instant) they somehow "forget" each other in their solo movies. there could be simple explanations why but it just looks weird sometimes.
I was thinking it would be awesome to have some villain plans and events bleed over into other movies.
Something like this:
After BvS, Lex Luthor, still free and with good publicity, is approached by the Legion, a collection criminals led by immortals like Vandal Savage, Ra's Al Ghul, Ares, and Circe. He's supposed to work
for them.
In Justice League, we see the villains observing the heroes versus a bigger threat, and we find out that they swept in to take their failed peers stuff afterwards.
In Batman, Talia is revealed to be working in Lex Corp, and the badguys are recruited by the Legion, making their name more literal than originally revealed. Also, it's implied that someone managed to steal stuff from the Bat-computer.
In Wonder Woman, Ares and Circe transform a mercenary warrior recommended by Ra's and Vandal into the Cheetah, and it's established she doesn't want to be a henchmen.
In Justice League 2, Lex is running for president and unleashes Batman's anti-Justice League plans. The league barely survives, but manage to cause the legion to self-destruct by revealing that Luthor was planning a coup. Lex still succeeds with the help of Talia, Cheetah, and the Joker as his kingmaker, but his new Secret Society is smaller and most go underground.
In Green Lantern, the Society allies with Sinestro to give him a foothold in Sector 2814, but he's driven away.
In Flash, Zoom actually ends up fighting Flash and the Secret Society affiliated Rogues, setting a precedent for heroes and villains working together.
In Trinity, Cheetah breaks with the Society because of a new ally they have named Libra, while Lex unleashes the Joker to cover his tracks as tries to completely evade Superman. With all three super-villains temporarily out of the picture, Libra approaches the remaining villains and a returned Vandal Savage about selling their selves into a deal for power.
In Justice League 3, Savage is possessed by Darkseid. Half the villains stay allied with him, the other half join the League in fighting back.
DC's got a bigger reputation for villain team ups, so something more integrated like this would be cool.