How badly do you want a Kyurem? Who doesn’t want a shiny? Well, some of you, most people at least want a dex entry. For PvE, its out classed most of the time by other dragons, really same goes for PvP. Don’t think you have to, but you could get a few just in case.
What do beat it with? Machamp is always on these charts, get some from some one, it’s been out a long time. Also look for Rhyperior’s community day move available this December community day.
Go to the official counters page for a complete list including Shadows and Megas to see how your Pokemon perform.