I’ve tried playing as a frost mage over the years, but it never quite worked out. I would do exactly what I saw the good players doing but would die rather quickly while their shield seemed to hold out for ages and they could kite for miles. My shield lasts half a second, they break my roots, and beat me to hell.
But in Legion it’s considerably easier to play. Someone mentioned it feels like a WoD shadow priest, and it does. If you take Glacial Spike, you ramp up to 5 icicles, then use it to form a big one (with a cast time) and let it go for a lot of damage. That doesn’t really work in PvP so I took Comet storm, but frost now has nice little procs for Flurry and Ice Lance, and with Frost Nova, Ice Nova, the frozen orb, Comet storm all on very decent cool downs, plus double nova, double blink, it’s very fun to play. It’s about on par with Fire, though I do miss Fire’s ability to spam cast Flamestrike. Blizzard is on a cool down.
World pvp is still bogus though. I have that video where a warrior took me to 20% health before I could even react, that frost mage that did the same when I was questing, and now a rogue who took nearly all my health before I could blink. I was at 40% and just fell over dead. So sad. I miss normal wpvp.