Oko, Lord of the Fae 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

Creatures can't attack planeswalkers you control unless their controller pays for each of those creatures. +1: Up to one target artifact or creature loses all abilities until your next turn. −1: Create a 2/2 white Ox creature token. −7: You get an emblem with "At the beginning of your upkeep, conjure a random planeswalker card into exile. You may cast that card this turn without paying its mana cost."