Personally, I think Ray is a little overhyped. Yes, it's incredibly powerful and fast, but Raichu and Vileplume are still in format, along with Glaceon and Regice, but Ranger takes care of the last two. The main reason I think it's a little overhyped is Klefki from Steam Seige. It's not an autoloss whatsoever, but it can prevent M Ray from attacking for a turn or two while they set up something else. With the lack of tool disruption in PRC-On, M Ray could struggle if they don't run a back up attacker. I think the best way to play around it is with Raichu because it hits for weakness on M Ray and Yveltal, but it's better than Zoroark because your opponent can control their bench, preventing Zoroark from taking a knockout.