Since this is wifi competitive (pretty sure...), there's a few things you can't change, but you can make use of. Unfortunately poison heal Gliscor is usually better, but it does run a sand veil set as seen (I'll list the other things just incase you aren't going w/ wifi):
Gliscor@Flying Gem
Sand Veil
252 Atk / 4 Def / 252 Spe
Adamant
- Swords Dance
- Acrobatics
- Earthquake
- Substitute
Gliscor usually doesn't find much use for Stone Edge, while EQ is there for coverage against things you'll face (and with a few SD boosts, can OHKO forry/ferro but usually used w/ taunt). Acrobatics is really really annoying (sadly you didn't get Adamant nature) but can still really hurt the opponent, substitute is there to pretty much protect you so you can set up.
For Vaporeon, using items such as nevermeltice doesn't really help at all, since it only boosts ice attacks, and you want its STAB attacks as good as they can be. The only Vaporeon that really suits what you want needs to be bred to get wish (iirc), so you could always go with another water Pokemon in that place.
Again on Hydreigon, darkglasses just don't really work, but the set you'd most likely go with is:
Hydreigon@Life Orb/Expert Belt
Levitate
4 HP / 252 SpA / 252 Spe
Modest
- Draco Meteor
- Dark Pulse
- Fire Blast
- Focus Blast / U-turn
This can utilise its two STABs, specialising in its special stats, hitting hard straight off with Life Orb, while Fire Blast can defeat the steels you'd otherwise have issues with. Focus Blast can hurt anything else that'd be likely to give you trouble such as Heatran etc.
For Lucario, with modest, using a physically inclined moveset doesn't really work, so the two sets you could go with are:
Lucario@Life Orb
Inner Focus
4 HP / 252 SpA / 252 Spe
Modest
- Nasty Plot
- Aura Sphere
- Dark Pulse
- Vacuum Wave / Hidden Power Ice
Or,
Lucario@Choice Specs
Inner Focus
4 HP / 252 SpA / 252 Spe
Modest
- Aura Sphere
- Dark Pulse
- Hidden Power Ice
- Vacuum Wave
Both are special, and both hit hard, it depends whether you want the extra boost, or to be locked into an attack, with vacuum wave used for priority, Aura Sphere for STAB and Dark Pulse for coverage, while Hidden Power Ice hurts the other things you'd otherwise attack. If you're sticking to wifi, then going with the first set is easiest.
For Luxray, you might be better off with Rotom-W, since it covers both water/electric for STABs, (as in you won't need Vaporeon) and can be pretty annoying, of course, with Rotom-W would come Scizor (U-turn + Volt Switch is an annoying combination but is effective since both basically resist each other's weaknesses), replacing both of the two. Scizor is also primarily physical, which can cover Chansey w/ Superpower that your others pretty much couldn't.
Emboar isn't really... good at all competitively. You could always go with Heatran which will help against dragons:
Heatran@Air Balloon
Flash Fire
252 SpA / 4 SpD / 252 Spe
Modest / Timid
- Fire Blast
- Earth Power
- Hidden Power Ice / Hidden Power Grass
- Stealth Rock
Generally fire blast is there for STAB power, while flamethrower can work. Earth Power is there to defeat other Heatran (predicted switch in!), while HP ice / grass can take down the things you have the issues with the most. Personally I usually go with HP ice but grass can be useful too against water types. SR is there to annoy the opponent, etc.
gl!