super funny to me how fuinjuutsu specialists are functionally the wizards even among the ninja wizard populace of naruto. give them some paper and prep time and they start playing with reality like it's made of dough. anyways, some things iruka does with his fuinjuutsu that are cool and fun and thematically resonant:
he gains the most renown for his seals, of course, but has carved out a niche for himself in learning how to enchant weapons and clothing. for iruka, who does everything he can for others, this was a natural progression. (fuinjuutsu, like anything else in this world made possible with chakra and grit, is about intention, and will, and some healthy disregard for the laws of reality. iruka's only desire had ever been to protect as many people as he could, to let them be as safe as they could be, to come home. of course he would learn to make their clothes tough enough to deflect blades. of course he would gift weapons that don't break, that could cleave mountains in two. violence is the way of this world, and iruka has learned about survival since he was a child; he will give others what they need to survive, until the world no longer needs such things. it will be considered a kindness until it isn't.) his fuinjuutsu mastery becomes so refined and covetous that the daimyos have received enchanted items by him, as well as the other kages, but iruka gives away most of his craft to the general populace, and most often for free, because they are the ones who need it most, and the most deserving besides.
if cursed seals exist, then surely the opposite can as well? iruka is willing to experiment and kakashi is more than willing to be the test subject. it's desire and willpower made manifest into ink, put onto skin, but instead of kakashi carrying around the remnants of ambition and greed, he has iruka's love for him, writ large and deep, so deep he can feel it to his marrow. there is no pain, just warmth and a soft pressure, like a kiss, like a hand on his shoulder. that blessed seal, like many other things kakashi carries on his body, will come to save his life many times. and if nothing else, it serves as a beautiful tattoo, inked on his left arm, covering his anbu mark. call it a shedding of the skin, at last, for a man who's worn too many it became so heavy. let it be a start to him writing a better ending for himself, with iruka's hand to help steady him, his generous heart reminding kakashi that he can want better for himself. iruka always could see the potential in everyone.
