Well considering the aspect (how it will look in a futur) and the typing I considered some stuff here is what I think of each of the Abilities.
Aftermath- Defensive Well, a defensive pokemon would be happy in my opinion to see that its life was worth something, maybe crippling with status then faint and damage a little.
Air Lock/Cloud Nine- Both Well, its not meant to be defensive or offensive, it just negates weather and aids both types. Perhaps since we have a Dragon type it can negate Hail and lower the accuracy to 70%
Anticipation- Both but I think defensive pokemon take more advantage of it, since walls like Blissey can anticipate a mixed set with SuperPower or something like that.
Battle Armor/Shell Armor- Defensive stalling and defensive pokemon hate more super efective hits than frail sweepers, lets face it they will die anyways, and defensive pokemon take more hits
Chlorophyll- Offensive the boost of speed clearly offers a Sweeper, however a Dragon/Electric type has no sense with Chlorophyll.
Color Change - Both the ability is tricky and versatile so it can aid on both types offensive and defensive however a Normal type would be better with that nature.
Compoundeyes- Offensive with a higher accuracy you are allowed to use more powerful moves that have low accuracy like Hydro Pump, Blizard, Thunder, etc
Damp- Defensive meant for doubles in my opinion, but blocking an explosion is always handy, anyways this should be kept for a Water pokemon
Early Bird- Defensive works well with Rest, so I would call it a Healing, Stalling or atleast Defensive pokemon.
Effect Spore-Defensive inflicting status is used alot more on defensive pokemon for a god purpose, inflict status as much as you can, an offensive won't use it quite as good as a defensive pokemon would, now again a Dragon/Electric with effect spore sounds awkward.
Flower Gift- Defensive Sort of the same as Effect spore.
Gluttony- Offensive that would make a perfect Belly Drum user, just look at Linoone, it makes a wonderful job thanks to Gluttony.
Hustle- Offensive, giving moves like Aerial Ace and Vital Throw that never miss along with Hustle sounds like a huge amount of power, however I dont find a Dragon benefitting from it.
Iron Fist- Offensive Go, Go, Go Thunderpunch! It is sure a neglected ability, and has marvelous effects, powering the Elemental Punches.
Leaf Guard - Defensive, curing status is better for defensive pokemon since they dont enjoy it that much. Anyways again a grass ability on a Dragon/Electric?
Magic Guard- Defensive I think there is no explanation needed
Marvel Scale- Defensive well, it boost defense so it sure calls out for a Defensive pokemon o take the boost.
Mold Breaker- Offensive well, there is one reason why I support this Ability, DIE TO EARTHQUAKE DAMN BRONZONG!!! sorry, I had to say it...
Poison Point -Defensive well, only Defensive pokemon will be able to take a hit to inlict the poison, so a Sweeper or offensive pokemon wont use it as much.
Quick Feet- Offensive again, as said in Chlorophyll the speed boost is best used by an offensive pokemon
Reckless- Offensive boosts power of recoil moves, so yeah...
Rock Head- Offensive moves like Double-Edge have huge power, eliminating the downfall of those attacks is great for any offensive pokemon
Rough Skin- Defensive read Poison Point please.
Shield Dust- Any?
Skill Link-Offensive I mainly see this move as a Sub breaker, using moves like Comet Punch and Rock Throw, hit the Sub and keep on hitting the foe, however Dragon/Electric seems like having no access to any of the multiple hitting moves in the game.
Solar Power- Offensive raising Speacil Attack is great, is like having Specs without getting stuck into one single move, however its again a Grass type Ability.
Soundproof- Both blocking Roar is good for stalling (defenseive) and Sweeping (offensive) pokemon since they can stay in batle and not loose their boosts
Static- Defensive same as Poison Point and Rough Sking, you need to be able to take a move.
Suction Cups- Any well, it would only work with a BP chain, not being able to be Roar'ed away is handy.
Synchronize- Defensive all of the pokemon with Synchronize are offensive, playing aroudn with it in a defensive pokemon would be nice.
Tangled Feet- Offensive sort of, needs no explanation
Thick Fat- Defensive I like the ability, first of all I must say I want the pokemon to be defensive since we don't have any defensive Dragon but Latias, with Thick Fat the Dragon/Electric can take Ice moves easier and almost no damge from Fire.
Tinted Lens- Offensive boosting power from not very effective moves is welcomed by offense.
Trace- Defensive since its used to wall some foes like Salamence, Heatran, Electivire, Gyarados, Arcanine, Jolteon, Vaporeon between others, however an offensive type coudl also benefit, but not as much as a defensive would.
Unburden- Offensive same as Chlorophyll, speed boost equal offense.
From all of the above, I my favorite three are Static, Iron Fist and Thick Fat lol @ a Fat Dragon!