2 Level 4 monsters
When a Level 5 or higher monster is Special Summoned: You can detach 1 Xyz Material from this card; negate the Special Summon and destroy it.
Clearly this is going to be the most searched for card during the GENF sneak preview. But to be honest, I think it's good but not as broke as people claim it to be.
First off, it's still a great card. It's definitely a must have in any extra deck, but not in 3's. If you have 1 Roach in your extra deck you're set, while 2 doesn't hurt if you're going for more control. Yes, it stops special summons of level 5 or higher by removing a material. However, it's still vulnerable to Xyz monsters.
It's still quite the power card, as it can stop essential cards like Librarian or Shi En. However, I think there's too much hype for this card.
Gadgets love this deck, as well as any "Anti" deck that could abuse Roach's effect. But it's still good to have in any extra deck, as previously mentioned.
I will be keeping my eyes out for this card, but I'm not willing to buy it...