Ciel and the Fairy Gym dear lord. Just play every gym as if it was Showdown or competitive. If you can't get around something, then try imagining the flaw in your team or even look at Smogon for where your team falls in the tier lists.
Think of it as a challenge! Reborn is just awesome in the way that it can be tough.
Oh! One last thing is abusing the field mechanics. For Shelly I swept with fire plume and my Growlithe. Set the field on fire and bamb. Donezo.