I'm level 88 and I haven't encountered Rayman enough at the higher levels to give a good counter. I will say, however, in the 30 levels I wouldn't worry too much about dealing with a specific hero. Your focus should be on figuring out who your top 5 are going to be and leveling them up appropriately. Additionally, you need to do all your daily quest so you can level up as quickly as possible. I can tell you one sure fire way to beat a level 30+ Rayman.... have your team be level 50+.
I know that's not the advise you are looking for but trust me the best advise is to make sure your leveling your party and the right heros as quickly and efficiently as possible. If you have some time on your hands check out soulhuntersdb.com and familiarize yourself with the heros you own and decide who your top 5 and 15 heros are.... and then focus on them. Good luck have fun and enjoy the grind
I've already focused on my top 15. I'm actually licking my lips with anticipation when I can start leveling up those heroes outside my top 15 and have a huge deck of 40 strong heroes handy. It will be almost impossible not to win the Crucible of Fire at that point