Can we talk about how this card could actually work as a real card? Of course, it would probably be banned in YGO tournaments.

It'd be banned because it's beyond broken; it negates all attacks and forces your opponent into defense mode every 3 turns. Most monsters either have good attack or good defense so by forcing them into defense you're potentially putting them into a situation where you can easily clear the board of enemy monsters every 3 turns for the rest of the game or until your opponent plays a card to destroy/disable your trap. Combine this with the fact that official rules may allow you to have between one and 3 of these cards in your deck (depending on if it's limited, semi-limited, or non-limited) you could severely limit the amount of turns your opponent is capable of attacking.