honestly there is 2 ways to beat it. One is to control sasori until he is dead, or if you are strong enough to kill sasori in one go before he is able to set out clones you can just ohko them 1by1. I was having trouble with having patience with the first method so i put on iruka tobi kanon firemain with full buffing and just did the second. It wasnt pretty but I did it. FYI Iruka was a good tai wall and soaked up a lot of the dmg.