the proper criterion to find a value

[tizzio1]

hi , i have to find a certain value for the american version of final fantasy 8 for psx with cheat engine ( i know i am supposed to ask in the forum of cheat engine , but i don't do that because none is helpful there ) , i want to find the values who contain the invincibility triggered by the item hero trail in order to permanently apply those values , the point is is don't get the proper criterion to find that or those values : if for example i want to find the value of a timer , i know that i must look for a value who decrease or in some cases increase , but in this case i don't really understand what kind of criterion determine the values i am looking for , for now i only managed to find the timer that trigger everytime i use the hero trail , and the only thing i can suppose is that i must find the values that trigger the invincibility and permanently set the value to have the hero trail active, so what kind of criterion i must think about to find that value ?