For all of you who depended on Garchomp defensively...
...check out this Flygon EV spread.
I know, it's offensively retarded compared to Garchomp, but it still 2HKOs Tyranitar with Earthquake, and OHKOs Lucario. It's 10% tougher than 6/0 Garchomp, and it has Roost too!
Anyways, here is the set.
Flygon @ Leftovers
Jolly Nature
204 HP / 16 Atk / 214 Def / 76 Spe
Earthquake
Roost
U-Turn /Fire Punch
Toxic / Fire Punch
Thanks to Roost and Earthquake, this thing makes a decent CBtar switch in, but where it really shines is against Lucario and Heatran. Thanks to the EV spread, it is bulky enough to take large beatings from these pokemon, but has enough punch to do something back.
The last two slots are up to you. Fire Punch gives you an answer to Skarmory and Bronzong. Toxic will wear down anything that repeated Earthquakes cannot, save for Poisons and Steels, which Earthquake should help against anyways. U-Turn is an excellent scouting move, and if you misjudge your opponent and find out they have a Tyraniboah, you can still break it's sub and send in an Ice resist to chase it off.
It's decent defensive typing gives it resistance to the Edge/Quake combo, as well as Fire attacks. Immunity to most forms of passive damage and Stealth Rock resistance keeps it around longer. Electric Immunity is nice to have as well, especially when trying to wear down annoyers like Togekiss with Toxic.
Here are some damage calculations:
-Tyranitar's 604 attack Stone Edge on Flygon: 36-43%
-Tyranitar's 604 attack Crunch on Flygon: 59-69%.
-Tyranitar's Jolly DD LO Crunch on Flygon: 70-82%.
This attack should be avoided, but you can survive it with health to spare.
-Lucario's +2 Extremespeed: 59-70%.
-Lucario's +2 Bullet Punch: 44-52%.
-Lucario's Close Combat: 67-78%.
The only way Lucario can win is if it Close Combats followed by Extreme Speed, rolling above average damage both times.
-Modest Heatran's Fire Blast: 36-43%
-Modest Heatran's Hidden Power Grass: 28-34%
-Modest Heatran's Hidden Power Ice: OHKO
-Modest Heatran's Dragon Pulse: 73-86%
-Modest Heatran's Explosion: 79-93%
Makes a pretty good switch-in to Heatran if you don't have anything better, or if you are unsure if they are going to Earth Power your own Heatran. Only Hidden Power Ice can take you down.
-Calm Mind Jirachi's Psychic: 36-42%
-Calm Mind Jirachi's +1 Psychic: 53-62%
Those annoying Sub CM Jirachi can be chased off all the time, provided you act quickly! Smart Roosting can ensure you have enough health to do it repatedly. If you don't switch in immediately, the faster CM Jirachi might beat you, so always respond with Flygon ASAP.
-Togekiss' Air Slash: 30-35%
This was a pleasant surprise. With Thunderwave immunity and higher speed, you can come in and chase it off, provided you can Toxic Stall it. Taking on Nasty Plot versions is suicide.
-Blissey's 40 SpA Ice Beam: 77-91%
-Donphan's Ice Shard: 36-42%
-Mamoswine's LO Ice Shard: 91-107%
-Gliscor's Ice Fang: 48-56%
-Hippowdon's Ice Fang: 55-65%
Just in case the situation should ever arise, you can survive weak Ice attacks. You need 254 SpA to OHKO with Ice Beam, 409 to OHKO with Ice Punch, and 762 to OHKO with Ice Shard. For STAB Ice moves, you'll need 169, 272, and 508 respectively.
I'm not trying to be a Flygon fanboy, but after remembering all the times I switched Garchomp into Tyranitar, Jirachi, Lucario and Heatran, I felt it needed to be mentioned, especially since Flygon gets Roost.