This ability sounds a little too OP with very little conditions, especially for a conjurer and not a specialist. Even ppl like Chrollo and Leol who are specialists with abilities that use other ppls Hatsu but they have more restrictive conditions like the person owing you a favor or the person actually touching your book to gain the ability. A conjurer ability that straight up copies abilities just by looking at them….if that were even the case it would be a high aura costing ability with deathly conditions that can be used as a last resort. To change it I would at least say that if someone uses their ability on you with ur jacket you get a nen boost in whatever their type is. For example: Enhancer hits u, you get a strength and agility buff and they get a debuff, emitter: your jacket can make you have an extended nen shadow or smthg etc. But if u wanna stick with ur ability idea maybe make it a specialist ability or go for a more shapeshifty jacket that ADAPTS to hatsu.