Anyone have any advice on how to use mega kang effectively. I always struggle to find a situation to set it up and it usually ends up getting burned or completely walled by a ghost type.
Screens can help a lot in setting up, as can Baton Pass. I've seen Boaziken BP Bulk Ups to Kang, and that can be really hard to stop. Sub is an interesting move on Kang, and can possibly score you free set up opportunities as well.
Quite a few ways to deal with burn. First is aforementioned Sub, but that doesn't help with stuff faster. Facade can use the burn or other status against the foe, as a 140 BP STB move with no drawbacks in that situation. Running something to switch in on the burn and/or heal Kang through Healing Wish or Lunar Dance is also good. Examples dpfpr these kinds of things are Cress, Clefable, and Chandelure. Going special on Kang is quite unexpected, and can get past most of its usual checks ok, though it is a lot weaker overall.
Ghost types are why you run Scrappy pre mega and don't always go mega immediately. Even without the Parental Bond few ghosts appreciate getting hit by a normal STAB, and even bulky ones are at the very least at risk of paralysis from Secret Power. Predicting a ghost switch and using PuP can also give you an edge. Crunch instead of the more common Sucker Punch prevents ghosts from playing around you with WoW and Sub or whatever.
The most common Kang can't really touch most ghosts at all once mega, but I really like Rock Slide, and that does a decent amount to Gengar while possibly flinch haxing most other ghosts. Odd special Kang can get around most ghosts with Shadow Ball, but is even easier for Mega Sableye to set up on, and Aegislash is still a problem. Both of those you can kinda deal with through some combination of PuP boosts, Secret Power or para support, and Rock Slide flinch hax. EQ and Crunch are also really nice for Aegi and lots of other ghosts besides.
EVs are ba big thing too. Some mons do max/Max spreads, but I don't think that's best for Kang. I run 140 HP/ 252+Atk/ 4 Def/ 12 SpD/ 100 Spe for instance.