The first three trainers were fairly straight forward. I tried to pick pets that had generic abilities and were double counters against the trainer pets. For the last four, I went with pets that had strong move sets. Attacks that increase damage taken really helped get past the buff that the Celestial "Boss Pets" had.
Here are the teams and strats that I used. I may change my teams up as the tournament progresses each week, depending on whether or not I need to use certain pets against certain trainers (or if I find better pets to use against specific teams). I know the teams and strats aren't the best, but this is merely what worked for me.
All pets are upgraded to rare. I didn't go for any specific breed, but I'm sure health, power and speed can be played to your advantage if you take the time to do some research and testing.
I used some suggestions from WarcraftPets as well as Wowhead comments to create the teams I used against the last four. If you have any suggestions for reliable and effective teams, please let me know!
ROUND ONE - Random Rotation of Misc Trainers
First: Lil' Tarecgosa (2, 1, 1)Started with Lil' Tarecgosa and Arcane Storm followed by Arcane Blast. Wisdom went down quickly. Continued attacking until Tarecgosa died.
Second: Mechanical Pandaren Dragonling (1, 2, 2)
Third: Curious Oracle Hatchling (1, 2, 1)
Switched to Mechanical Pandaren Dragonling, and if Patience's Clean-Up was on cooldown, I dropped Decoy. If it wasn't, I used Thunderbolt first instead. After that it was just a matter of Decoy when off cooldown and then Breath until Patience dies. Continued attacking until the Dragonling died.
Last was my Curious Oracle Hatchling. I only needed to do two hits to Knowledge to defeat it. Backflip interrupted Knowledge since my Hatchling is faster, and then a quick Punch finished the fight.
Dr. Ion Goldbloom
First: Emerald Whelpling (2, 1, 1)Started with my Emerald Whelpling against Screamer. I knew at some point it would use Feign Death and Swap to the direhorn, so I made the most of my attacks against Screamer. Used Emerald Bite first and foremost. And since my opponent's team doesn't have any healing abilities, I then attacked with Moonfire. Even though Screamer used Lift-Off before Moonfire could hit it, the weather change gave my Whelpling's next attack, Emerald Bite, a damage boost.
Second: Tundra Penguin (1, 2, 1)
Third: Tranquil Mechanical Yeti (1, 1, 2)
Once Screamer swapped out and Trike stepped into the active field, I switched to my Tranquil Mechanical Yeti. Damaged Trike until my Yeti was down, but the direhorn had a sliver of health left. I swapped in my Tundra Penguin really quickly to finish him off.
Screamer was sent back in again, and I used my Emerald Whelpling to do as much damage as possible before its death.
In the end, I think it took my Tundra Penguin to finish Screamer off, but that's ok because it helped ramp up against Chaos. I used Slippery Ice and Ice Lance against Screamer, and the debuff from Slippery Ice stayed up once Chaos stepped in.
My goal against Chaos was to destroy its accuracy. It already has an ability, Uncertainty, that debuffs its hit chance for one round. Slippery Ice reduced Chaos' hit even more, and its attacks missed so many times against my Penguin. I kept the debuff up on Chaos, and proceeded to spam Ice Lance until it was over.
Sully "The Pickle" McLeary
First: Huge Toad (2, 1, 2)I used my Huge Toad to first dot up Socks with Swarm of Flies, then Tongue Lash, while using Healing Wave on cooldown.
Second: Flayer Youngling (2, 2, 2)
Third: Jade Crane Chick (1, 2, 2)
My Toad still had health left by the time Socks went down, so I used it to absorb Monte's Burrow. I then switched to my Flayer Youngling which took out the rabbit with Rampage. The Flayer Youngling stayed in and threw some damage up onto Rikki before dying.
Finally, I it was my Jade Crane Chick's turn. Jadeskin, Flock, and then Slicing Wind made quick work of Rikki.
ROUND TWO - Celestial "Boss Pets"
First: Zandalari Kneebiter (2, 2, 2)Black Claw and Hunting Party were the top priority attacks, and both the first and second raptor finished off Zao with no trouble. I didn't even need the third raptor, but had it in place just in case RNG decided to turn its back on my team.
Second: Zandalari Anklerender (2, 1, 2)
Third: Zandalari Footslasher (1, 1, 1)
First: Gregarious Grell (1, 2, 1)My Gregarious Grell nearly solo'd Yu'la using Phase Shift to avoid Lift Off, and then Punch with Cauterize whenever necessary.
Second: Hopling (1, 2, 1)
Third: Moonkin Hatchling (1, 2, 2)
Once the Grell was down, I brought in my Hopling. Being faster than Yu'la, Backflip did wonders, and I finished it off with Crush.
I had my Moonkin Hatchling just in case the other two pets ran into some bad RNG.
First: Sunreaver Micro-Sentry (1, 2, 1)This fight was, by far, the most troublesome. Not only does Xu-Fu hit hard, one of his attacks is a self heal. To top it all off, he uses Moonfire which increases that self heal. It was the most frustrating battle out of the four Celestials, and luck may have been the only reason I beat it in the end.
Second: Westfall Chicken (1, 1, 2)
Third: Darkmoon Tonk (1, 1, 2)
I tried out using a strat suggested on the WarcraftPets forums, but RNG decided to get in my way. Only on the very last attempt (after 4 or 5 failed attmpts) did it work.
Xu-Fu always starts out with Moonfire, and to counter that, I used my Sunreaver Micro-Sentry to change the weather (Call Lightning). Then I immediately switched to my Westfall Chicken and attacked with Flock.
Thankfully, my Chicken dodged a few of Xu-Fu's attacks (including Feed, which heals it), and I was able to use Flock once (lasts for 3 rounds) and then again (another 3 rounds) before my Chicken died.
I then swapped the Micro-Sentry back in for Call Lightning and then Laser to finish Xu-Fu off.
One thing to note is that I tried this type of set up multiple times with different pets. The concept is the same, Call Lightning, Flock (or some ability that causes Xu-Fu to take bonus damage), and then finish up with another Call Lighting and misc attack. However, the tiger hits damn hard, and can ruin your plans completely. A crit on your pet or a missed attack on Xu-Fu could easily spoil the strategy.
I'm looking for a more reliable set up to use against Xu-Fu, but for today, I was just happy to finally defeat him.
First: Sen'jin Fetish (1, 2, 2)This team was courtesy of a Wowhead comment, and it worked perfectly.
Second: Jade Oozeling (2, 1, 2)
Third: Darkmoon Eye (1, 1, 1)
I used the Sen'jin Fetish first, but the initial attacks don't really matter too much. You could just Shadow Slash the entire time and that would be ok.
I had my Sen'jin Fetish use Rot on Chi-Chi and then Shadow Slash on repeat until my pet died and revived using the Undead passive. On its final turn, I used Wild Magic. It's very important to get Wild Magic up, as it will make your following pet's job much easier.
Next up was the Jade Oozeling. I use a P/P oozeling, but I think any breed will work. Tossed up Acidic Goo first and foremost followed by Corrosion. Chi-Chi is likely to use Ethereal, which means one of the dots will be dodged, but that's ok. Just toss it up on the next round, and so long as you can maintain both dots on Chi-Chi, his health will drop like a rock.
Chi-Chi died to the dot ticks combined with Wild Magic (they damaged through his Tranqulity easily), so my last pet wasn't even needed. But in the event I did need a third pet, Darkmoon Eye was a great way to finish the Celestial pet off. But any hard hitting magic attack will do.