you need to make him like you more(by paying him loads of gil in battles.)and in the next battle pay him loads of gil and if yojimbo likes you enough(the more he likes you the better the chance.)hell use it(there a higher chance of him using it if if his overdrives near full.)to make him like you(to tell how much he likes you see how much damage he does and if he does decent attacks for a small amountof money.)if he uses daigoro it means the relationship drops aand the freindship drops loads if you only pay him 0 gil because he walks off if you do that.if he useshis other 3 attacks that means hell like you more(which means hell do more damage and use good attacks like zanmato for less gil.)