Villainous Syndication is one of those cards players keep asking about. Here is, in plain words, what its official text says, the rulings published by Wizards of the Coast, and the combos players actually run.

Official card text

Tap an untapped Villain you control: Mill a card. Put a plan counter on this enchantment. Activate only as a sorcery. (To mill a card, put the top card of your library into your graveyard.) When the fourth plan counter is put on this enchantment, sacrifice it. When you do, return target creature card from your graveyard to the battlefield.