On the top of my head:Thinking of making a Mega Lopunny team, but I've been out of the competitive scene for a while so I'm not sure what is has trouble getting around. I'm assuming really tanky things like Skarmory and (Mega)Slowbro, but if you guys could narrow it down a bit more, I'd appreciate it!
-Birds talonflame in particular
-Mega Salamence can set up a DD on you (especially on mega turn with intimidate) and threaten a sweep
-Scarf Latios, Terrakion, Keldeo
-Stallbreaker mew
-Mach punchers (breloom and conkeldurr)
-This cannot be circumvented but random protect on high jump kick is painful
A lot of things check it meaning that you'll mostly want it to come in cleanly (after a KO or slow volt/turn).