Not too much "coverage" for a mono-dragon. It has a lot of physical attackers that almost run some of the same sets. I suggest having a mix of 3-special attackers and 3- physical attackers to even thing up.
Salamance doesn't exactly need fly, and can get easily revenge killed by a slower pokemon's ice beam. Try something different, like zen-headbutt or stone edge. I'd go with either of those. Outrage is a nice idea, hit's pokemon hard, but the confusion is annoying. Instead of the Flyinium-Z, try a lum-berry to get rid of that for the first time it uses it. Salamance has great attack already, so it doesn't need the adamant boost. It's speed though, it needs a nature to help it.
edit:: fly + z-move can be like a one time thing, sorry, I didn't think much about the combo.
Kingdra seems to be leaning toward a special attacker. Let's make it that instead of mixed. Draco Meteor is good, and adding Surf or Hydro Pump could make it even better. Clear Smog or Flash Canon deal with that fairy weakness. Might wanna use one of those. Hidden power grass is unnecessary since many things resist grass.
Everything seems good about your Mega-X, but changing the nature to jolly to help it's speed would be an improvement. Changing roost to E-Quake would be better. Don't worry about the recoil of Flare Blitz too much. You can always swap when things seem bad for it, or use E-Quake/Dragon Claw
Silvally reall just needs Draco-Meteor changed to something else. U-turn or Parting Shot could be a good option, and a way to get outta something. Even Pursuit on expected swaps. How about a Jolly or Adamant nature?
Latias is looking good, seems like the tank of the group. Getting rid of grass-knot for pyshic or toxic could be a good idea, since she's bulky. Draco meteor can be Ice-Beam. Has more coverage. Or you can change her to a special sweeper.
Haxorus!! Love the set, love what you're doing with it. Change Facade to something more reliable though.
Maybe try Garchomp on your team for the ground type. Could be useful!!
