Combo this card with Windmill Genex. That way, your opponent can not only NOT use his two face-down spell or trap cards, but the monster also receives an extra power boost.
If this card is face-up meaninglessly, use it as destruction fodder for Scrap Dragon.
To reduce the hassle of your opponent chaining your selections, activate this card at your opponent's End Phase during the turn in which those selections were set.
If you have one face-up already locking 2 cards, set a 2nd Xing Zhen Hu and during your opponent's next turn, if they only set 1 card, you can still activate the 2nd to lock the new card and one card already locked by the 1st Xing Zhen Hu, effectively double-locking a single card. Alternatively, If they target the 1st Xing Zhen Hu, you can chain the 2nd one to target the same two cards the first one was locking to keep those cards locked.