Luxray

Summary
While Luxray has no problem surviving in a 4th gen playthrough, the lightning... cat(?) never quite had the goods to cut it. With Charge Beam as it's only real boosting move and a rather lackluster movepool, it simply wasn't balanced correctly. Now, with 130 base attack along with Sucker Punch and ExtremeSpeed, Luxray functions as a powerful priority user.

Added Moves:

 * ExtremeSpeed
 * Sucker Punch
 * Bulk Up
 * Hone Claws

Luxray Strategies and Sets
Luxray is now able to hold it's own, and works especially well with Substitute. 

Bulk Up
Luxray @ Leftovers Trait: Guts EVs: 252 HP / 76 Atk / 176 SDef Careful Nature - Substitute - Bulk Up - Sucker Punch - Wild Charge Luxray's additions of Bulk Up and Sucker Punch allow it to pull off an interesting bulky attacker set. Electric and Dark moves have reasonably good neutral coverage, and the pseudo-priority of Sucker Punch helps get over Luxray's unimpressive speed. Guts is there mostly as a failsafe-Luxray will end up being a big Will-o-Wisp target.

Other options include Crunch, Superpower, and ExtremeSpeed.  

Guts
Luxray @ Toxic Orb Trait: Guts EVs: 4 HP / 252 Atk / 252 Spd Jolly Nature - Extremespeed - Wild Charge - Sucker Punch - Superpower This is a typical Guts + Toxic Orb set. As usual, if you are particularly good with prediction, you can swap Toxic Orb with another item and attempt to bring in Luxray to absorb a Toxic.

With both Extremespeed and Sucker Punch, Luxray manages to bypass its mediocre speed and hit ridiculously hard thanks to Guts. Wild Charge and Superpower work well for coverage (and of course, STAB for Wild Charge.) 