Can a strong ninja / ninjato sword have a simulated temper?
alright I think I get what you are trying to ask a modern sword of any type can have a single temper as opposed to needing the differentiated one I think you mean the hamon when you say simulated temper which is just there to look like the one caused by differential tempering simulated hamons(usually acid etched) are put there only for show the temper on those blades was made in a different way but they stll wanted the old look so they put it there all in all the end result is that differential hardened blades have a slightly higher chance of taking a set(bend that does not spring back) than their counterparts so use whatever you want unless it is a stainless steel wall hanger it should perform well
