I pulled this from another thread regarding the respec. Alot of good information I missed.
Heres a link to the Original thread, followed by the pertinent content:
Friggin_Taser's Guide to the Respec
Kill the Cot around the tree first. It just makes it easier. Then just keep killing vines. Kill them and move. Keep moving. You should have enough time to kill all the vines if you don't delay anything.
It's not that hard a trial. I've been in respec teams where the last mission took less time than the kill Cot mission at the beginning. Try smaller teams if you are having problems with the amount of vines. Less team members = less vines. A team of four, with a corruptor, dominator, and two brutes can handle the spirit tree.
What follows is my Beta CoT Respec Trial Guide:
The Level 25-30 Respec Trial
Contact is Sparcetriel in Nerva Archipelago
/loc is -1257.3 11.0 6410.6
Mission #1 Defeat 25 Circle of Thorns
Sparcetriel: I will tell you of a place where the Circle of Thorns routes their mystic powers to create great and fell effects. Through brute force and evil will, you can steal this power from them, and use to re-forge yourself. But before I tell you where to find this place, you must show me you have the might to succeed. Defeat 25 members of the Circle of Thorns, and return to me when you are done.
I care not where you defeat them, so long as it is done. Return when the task is complete.
Mission #2 Defeat Hero attack leaders - Nerva Archipelago
Sparcetriel: The place I am sending you is called the Tree of Thorns. A demonic tree, the Circle uses it's barbs and nettles to create their thorn blades and spirit thorns. But you are not the only ones who know this. Even now, a great host of the good and the just prepare to attack the Thorn Tree themselves. Before I send you to the tree, you must attack them to prevent interference.
Three forces now meet to plan their attack: Longbow brings their powerful heroes, the Legacy Chain brings their mystic acumen, and the Wyvern their detailed knowledge of battle. You must defeat Longbow's Ballista hero, the Legacy Chain's arcane specialst, and Wyvern's tactitian. Arachnos have provided an undersea vessel to take you to the base where they lair. Once the forces of good have been overthrown, return.
Mission #3 Take the Nexus of Thorns - Nerva Archipelago
Sparcetriel: The Thorn tree is a living nexus of mystical power beneath Thorn Island in the Nerva Archipelago. Once a bastion of the ancient Mu, the Circle now draw it's energies for their own mystic experimentations. The energies devoured by the tree are encysted within the heartwood in a thing called the Nexus of Thorns. To take this power as your own, you must weaken the three, then broach it's defenses. It will not be easy. So prepare yourselves, and tell me when you are ready to make your assault.
To reach the Nexus of Thorns, you must first weaken the tree itself. Once you are in it's chamber, destroy all the vines, but work in haste for they will re-grow.
Next, you must break through the outer layer of the tree, both to reach the Nexus of Thorns and to open the flow of energy.
Then take the Nexus and it's power will allow you to remake yourself.
You may only benefit from this 3 times. Once from me, and later from... Others. Though if you wish to shepard fellow villains through, I will still provide information.
The respec contact is Arbiter Lupin who can be found at /loc 2977 18 7020 in Nerva Archipelago.
Choosing character respecification as a prize will net you the Thorn Robber accolade badge.
Souveneir Clue:
The Nexus of Thorns
The demon Sparcetriel was willing to share it's secret knowledge as part of it's revenge against the Circle of Thorns. The first thing it wanted to do was prove your ability by defeating members of the Circle. You handled this, and returned to the fiend.
Next, you had to stop the united forces of Longbow, Wyvern, and the Legacy Chain from interrupting your attack with a strike of their own. You defeated the operation's leaders, clearing the way for yourself.