Mega Glalie has arrived! When ice Mega is needed, this is one of them, super easy to get, shiny, and will be a good cheap counter if you can get your hands on some candy while they are out!
Fire and fighting top the list here, with the ever useful Metagross popping up to mash things again. Should be ok with just 2 people, get that candy!
Go to the official counters page for a complete list including Shadows and Megas to see how your Pokemon perform.