I'm trying to catch a level 70 Rayquaza. I have a level 55 Kyogre equipped with Quick Claw.
My gameplan is this so far: use Ice Beam to get the Rayquaza to below 10% health, wait for the Rayquaza to use Rest to put itself to sleep, use Ice Beam again to get it to critical health, and finally chuck Ultra Balls at it repeatedly. However, I have tried this for many repetitions without any success.
What improvements can be made to my method to maximize the probability of successful capture?