And now I feel the need to point out that ‘Hey, stab yourself into one of these chairs and you’ll shatter into a million pieces’ isn’t exactly the best sales pitch. :P I do have an alternative in mind if you could change it to a more normal ‘find the chair that calls out to you and take your place in it’ speech, however.  And Vholdran also won’t need to mention the need to swear an oath, because his divinations will have shown that Muramasa and Torahime will be fulfilling that prerequisite without needing any prompting.