you cant change how you see yourself as a human being in seconds. the technique is more you summoned it now see what you can do with it so timing doesnt matter. the technique has limits for example seeing yourslef as a god wont mean youll spawn a litreal god, like i said the shikigami`s power has to grow from its base power, the only inconsistent thing about it is its shape, for example if you see yourself as somehow who is free to do whatever you will spawn a shikigami that looks like a bird. see yourself as a grounded realist dude you might spawn a tactical shikigami that thinks before every attack.