Oh, I remember some good luck.
4 VS 4.
Groudon & Ho-oh, Latias & Deoxys Defence
Against
Snorlax & Slowbro, Marowak & Slowking
Right off the start, Groudon Sword Dances up (he has good speed and defence). Ho-oh uses Sacred Fire on Snorlax, which didn't do much damage (I wanted to burn him).
However, this is where it falls apart. Snorlax cursed once. Slowbro used Trick Room. Now, Snorlax used Return, which got a critical Return hit, almost OHKOing my Ho-oh. Ho-oh tries again on Snorlax, and is successful this time. Slowbro did a move (I forget which) against my Groudon, and got a Critical Hit, OHKOing it.
I send out Latias, not knowing what Snorlax had. I used Calm Mind. I knew once I did this, nothing can stop me, unless someone uses Crunch... which Snorlax all of a sudden used. OHKO. I did not expect that. Slowbro used Shadow Ball which KO'd Ho-oh.
Now this is where my luck turns very good (or bad in some ways). My Deoxys Defence was the only thing left. Thankfully, Trick Room ended here. I use Cosmic Mind to raise my defence. However, Snorlax used Crunch and Slowbro used Shadow Ball. I barely had any HP left. I gain a little HP with Leftovers, and also Recover. Snorlax and Slowbro kept hitting me with Crunch and Shadow Ball.
However, both took a break. Slowbro used Trick Room again, and Snorlax used Rest to get rid of it's Burn. Unfortunatly, he had a Chesto Berry, but I still got the chance toToxic Slowbro, and used Cosmic Mind once. From, here on, I had to keep recovering for 4 or so turns. Finally though, firstly, Slowbro started to slack off instead, as Toxic kept endangering it from fainting. Snorlax ran out of PP for Crunch, so he had to use Return (which while it still hurt Deoxys, it wasn't doing as much). I got the chance to also Toxic Snorlax, and Cosmic Mind one more time.
Finally, Slowbro fainted, which means no more Trick Rooms! Now, they send out Marowak. Snorlax rests, while Marowak uses Stone Edge, which got a critical hit, almost OHKOing me again. Thankfully, Deoxys recovered again, and was fine.
I was able to Toxic Marowak, and Cosmic Mind up once or twice. Finally, I even got a chance to perform a subsitute. Marowak eventually died of Poison, and Slowking was sent out.
Slowking was not nearly as deadly, as it had neither Trick Room nor did it have a Recovery move. I toxic Slowking to death. All that was left was the annoying Snorlax with his rest.
I tried toxicing Snorlax, but he'd rest it away. I decide to then NOT do so till he ran out of PP. Finally, after 5 or so turns (with the help of Pressure), he ran out of PP for all his moves, and I also added a nice Toxic in there. Snorlax KOs himself with Struggle, and I win with just Deoxys, lol.
...wow that was a lot longer than I should have made it. Oh well, lol. :/