Each Player reveals 1 card from their hand. If one card is higher Level than the other, the card with the lower Level is sent to the Graveyard, and the player who revealed it takes 1000 damage. (Non-Monster Cards are treated as Level 0.)
You will have an idea on what your opponent is playing when he/she reveals a card.
It can disrupt your opponents combination when you make him/her discard a card.
The damage that it can inflict is 1/4 of your opponent's starting Life Points, which is pretty high.
You have to reveal a card to your opponent which will give him an idea on what you are playing.
It's a dead card if you don't have a monster card in your hand.
The revealed monster of your opponent might have a higher Level than yours, which makes its effect backfire on you.
If you activate this while your opponent has 1 card on hand then chained with an effect that makes your opponent discard a card. Ante's effect will be gone. E.g. Ante chained by Eliminating the League.
If you are using 3sd, you are likely using level 7 monsters (for Double Summon), making it weak to 8+ monster decks (like Kaibaman/BEWD), and ineffective to other lvl 7 monsters (if they tie, the card does nothing).
Hardly OP. Not unless you run Gate Guardian or something.