Lil Deathwing is incredible for 2-pet tamer teams due to his high power, efficient moveset, and the way tamers respond to stuns. I use him in my 'best' teams for more than half of the Pandaria/Spirit tamers, and decided to make a point of 2-petting all the tamers with him. Most of these teams are very fast and reliable and feature Lil DW as a primary component, but I did shoehorn him into a couple of the fights (e.g. Earth Spirit, Nishi).
He's always Tail Sweep/Roll/Elementium Bolt.
Hyuna*, Moruk, Zusshi: Lil Deathwing + Yellow Moth
This is the type of fight that really shows off Lil DW's damage potential. Use Elementium Bolt, Roll, Tail Sweep: this deals roughly 1500 damage and stuns the opponent, which causes the tamer to spend their turn swapping pets. So you get a free turn to Tail Sweep their 2nd pet, with Roll and dragonkin passive buffs active, which is ~880 damage. Lil DW typically lasts one more turn, which is Tail Sweep for another ~580, leaving the tamer's first two pets at less than 300 health. Yellow Moth then easily one-shots those 2 pets and massacres the last pet, which is aquatic. * For Hyuna, use Bolt, Tail Sweep, Roll, or else the firefly will die from Elementium Bolt and Hyuna won't lose a turn by swapping pets.
Yon, Shu: Lil DW + Lil Bling
Same tactics, but Lil Bling mops up because the last pet is a beast. Shu can beat you if his elemental stuns Lil DW; it's easy to replace Lil Bling with a slower/more reliable pet if desired.
Fire Spirit: Lil DW + Chrominius
Water Spirit: Lil DW + random flyer with liftoff or a dodge move.
Air Spirit: Lil DW + Emerald Proto-Whelp
I would use Chrominius here, but he occasionally manages to lose to the moth if he gets slept by Moth Dust. EPW is almost as fast due to the dragonkin passive anyway.
The above 8 fights end very reliably in 10-12 turns, as long as Tail Sweep hits (95%) and you don't get unlucky with opponent crits/Moth Dust procs (this is mainly Water Spirit, Moruk, and Shu). I probably have to restart one fight per day, on average -- I don't mind this tradeoff, especially since you know if you're going to win by turn 5 or 6.
Aki: Anubisath Idol + Lil DW
You can use mostly the same tactic as above, however Lil DW will die very fast to the dragon if the Shattered Defenses debuff is on him. So I use Sandstorm to prevent the debuff from being applied: Sandstorm, swap, Bolt, Roll, then spam Tail Sweep to finish the cricket and kill the dragon. Lil DW often survives to launch a Bolt at the otter, but either way Anubisath kills the otter easily.
Earth Spirit: Darkmoon Rabbit + Lil DW
Lil DW can't handle the Earth Spirit itself, so Darkmoon Rabbit does that (Huge Sharp Teeth, Burrow, Dodge, HST spam), then kills half the ooze (Dodge, HST, Burrow), and then backrows with ~500 health. Lil Deathwing then does Roll, Bolt, Tail Sweep to kill the ooze, and then a dragonkin-empowered Tail Sweep + Bolt hits the rat. The 2nd Tail Sweep comes close to killing the rat, and then the rabbit can finish it off.
Admittedly, this is a not a fight where I'd normally use Lil DW -- usually it's Darkmoon Rabbit + Warbot (Rabbit gets the ooze down to ~400, then Warbot lays a Minefield and builds a rocket before killing the ooze).
Nishi: Purple Puffer + Lil DW
This is the cheesiest team, because Purple Puffer can basically just solo it with Pumps and heals. Alternatively, you can start Lil DW and let Puffer mop up, but it's not necessarily any faster.