User blog comment:Xilinoc/Ch. 664 - The Gift/@comment-3177945-20160226190312/@comment-5398287-20160226223904

It's not that The Deathdealing somehow can't affect Urahara or something, it's that trying to kill him that way would be futile - unlike Nimaiya, Urahara's a genius when it comes to adapting to new situations in battle, which Askin pointed out earlier, so if, say, his sweat was made poisonous or something, he'd probably just be like "oh hey a drug I made on the spot that makes my sweat immediately evaporate for the next 5 minutes" (he did something similar with Yoruichi not too long ago). On the other hand, Gift Ring is pretty much just concentrated, extreme damage, which Urahara can't really counter aside from using a POOOOORTABLE GIGAITM. Askin's just being practical here.