When the Sand Griffin lands, slow down time. Go up to it and start slashing it. If it slashes at you with its claw or tail, roll out of the way. Keep hitting it with time slowed down. Once it has taken enough damage, it will go into the air. Go to the edge and hang off. You do not have to worry about it hitting you. Once it lands again, slow down time and attack. Keep doing this until it is defeated.