Does this card works on effects that passively increase attack too?
Like Lunalight Saber dancer or Dark Cavalry that says "for each x card gain attack".
Will this trap make them increase defense instead of attack?
To answer this guy's question, I believe Inverse universe works the same way as Magician girl's halving. If this is correct then no matter how much cards are in the gy, they will stop gaining atk or def.