Unless your pets can slow. The walls can be slowed, easily 
Both times I've done the trial with my ice controllers, the walls only ever had one spawn before we took them down.
I kind of disagree about the "don't use pets" at doors.
I've run this TF 7 or so times now, not one failure, with many different make ups of team members. I've had only one bad experience at the mold wall due to the Shrooms and that particular team not having enough mez protection (don't think we had any pets on this team).
There WILL BE spawns when you get close to either wall and when you attack either wall. The longer you take to take out the walls, the more spawns there will be; regardless of any pets.
What's important is that damage dealers concentrate on the walls.
All Control powers, AoE Debuffs/Buffs, and Pets are FANTASTIC at concentrating on any and all spawns that come about while either wall is attacked. (For the Rock wall, the Quarries MUST BE defeated prior to tackling that wall; for the Mold wall, the Lichens MUST BE defeated quickly before tackling that wall.)
If a group is going to utilize pets, do so away from the wall...use them to aggro/contain the spawning mobs. Let the damage dealer heroes deal with the wall.
I've already forgotten about most of you
Just wanted to mention that Cleat's visual "tour guide" of the Eden Trial is awesome. I'm planning to run this soon, and that helped me visualize a lot of things people were talking about much better.
I ran this last night with an awesome team, and I have two words for all of you: fulcrum shift.
I'm pretty sure our kin/psi did more damage than everyone else on the team combined. Fulcrum shift/psi wail was literally MELTING hundreds of DE.
Just ran a group through the Eden Trial succesfully last night, and it only took an hour and a half due primarily to this guide. Now about that sewer trial...
i5 tips.
I did 3 raids total, first 2 failed...#1 because we thought we could kill the titan quick enough to avoid the crystals (wrong) because our tanker had to leave. #2 never got past mold wall-healer kept getting killed on the way back from hospital (and she was the one with tp friend- i respecced for tp friend just because of that.)
Notes:
Walls can be end drained and will not spawn anything that way.
If you can't slow/end drain walls, the best method is to get your tanker (or 2) to taunt as they pop and have a defender buffing/healing him as he punchvokes and taunts.
If the NPC heroes die you will NOT fail the mish.
Anyone over 41 won't get the enhancement, I believe.
Lichens don't spawn unless someone aggros them. No ambushes.
Any defender is useful. Storm has the debuffs and knockdown, dark has -acc (very useful for quarries/walls), Kin is insane if you have a tanker with foot stomp! and rad makes the scrappers do the happy dance (smashing damage does extra on crystals, and with -res...
Empathy isn't really the best for, I'd go with a kin or rad anytime. Mutation is great against the titan, since integration nulls the stun thing.
That prismatic blast thing, the range is weird. Is it a cone? or a 180 degree thing? because a flyer got one shotted by it, and it was aimed at the tank.
Also, there are TWO quarries in the rock wall room now. One on a special, showy platform, and one to the left of the wall itself. Easy.
One, you don't NEED a controller. We had an illusion controller who didn't hold at all, we destroyed the Cairns and laid waste to everything in the entire cave.
About, the inv/ss tank that someone posted- not true. We played with an ice tank and did just fine.
The key:
Have 4 people focus on the wall while 4 focus on the DE around.
Our team:
Ice tank
1 illusion controller
2 blasters
1 emp defender
1 rad defender
2 scrappers
That was our team and we finished the entire bloody trial in less than 2 1/2 hours. Our team did ok because my emp kept all the squishies with cm the entire time basically.
We had 3 deaths, only froum our own stupidity/boredom. MoG ran out and 2 squishies left the team and got thwarted by mobs.
If you know your role on a team and do it well, you can defeat anything. Most of our team was Forgotten Legion, that's why we rocked.
Helpful things to have:
1. If you are subject to sleep/holds, you should have a bandoleer of breakfrees
2. Group Invis helps for when you're going down the shafts and trying to regroup.
3. If someone has recall friend, things can go a little quicker.
Have fun, everyone is right that this is one of the best trials/taskforces in the game. Enjoy it. If you haven't done it, you must experience it at least once.
Can you negate the regen rate if you cast Lingering Radiation?
Originally Posted by Megajoule
We're being invaded. Again. This time, instead of aliens, zombies, or eyeballs with teeth, it's the marching band.