You can use this card to effectively negate effects that target your "Ninja" monsters. If you Chain this to something like "Sakuretsu Armor", you'll get a stronger monster and your opponent's card will do nothing. However, this will only work with cards that target, and not something like "Smashing Ground".
You can activate this card during your Battle Phase. Activate it after your desired ninja monster has attacked to transform it into a new monster that can attack in the same Battle Phase.
Use "Emergency Provisions": to get rid of useless "Ninjitsu Art of Transformation" cards in your Spell/Trap Card Zone in the event that they are unlinked from the monster you special summoned with its effect. "Magic Planter" might be a better choice if you want card advantage.
If your opponent targets this face-down card for destruction or removal while you control a level 5 or higher Ninja, chain this card to summon "Sacred Phoenix of Nephthys", for it will be summoned then destroyed by the effect of this card. Then during your stanby phase, it is revived and will destroy all other spells and traps.
Combo this card with "White Dragon Ninja" so that only your opponent's traps and spells is destroyed.