Taking this sealing style a step beyond mastery, those completely confident in their Fūinjutsu skills are capable of modifying the formulae of the seals they make with the elements within the seals themselves. These modifications serve not only to change the seal as a whole, but also the properties of the elements within. This should only be attempted by a true master of Fūinjutsu, however, as those without the proper level of skill are liable to cause explosions due to a botched seal.