Well, since the tower (that I remember offhand):
Marjorie and Kasmeer are the main characters during the tower (Braham and Rox are there too, but you only see them inside the tower sometimes), Marjorie as poisons expert trying to find an antidote for the tower’s toxins, and kasmeer as a mesmer trying to get trough the illusion cloaking the tower (when you talk to marjorie she says that the “mesmer collective” called for her to go there). Eventually Kasmeer breaks trough the illusion and reveals the tower.
In the next step they’re in the camp right outside the tower, and sometimes appear with you inside the tower. BTW, The random conversation between Kasmeer and Marjorie makes it look like they’re more than just close friends, along with some other tidbits of information about them (like the fact that Kasmeer would never take her good clothes where they could get dirty or wrinkled, so she’s actually naked and her clothes are a mesmer illusion).
During the tower of nightmares anytime you entered into a chamber (instanced solo content), you got 1 or 2 companions with you randomly selected between Braham, Rox, Marjorie and Kasmeer. The chamber’s toxins made them hallucinate, Braham kept seeing his mother (Eir) watching him unaprovingly, Rox the same but with Rytlock, Kasmeer saw her father telling her to wait there for him and then leaving, and Marjorie the kid whose dead made her leave the guard (read her story).
Later they both help you kill the plant/kraitt hybrid that Scarlett was creating within the tower (Scarlett, as usual, escapes while monologuing about how it was all according to her plan) and inject anti toxin directly into the tower’s center, but that doesn’t kill it. You go back with them later and find clues in a lab nearby where Scarlett had items of all the other alliances/things she has made (aetherblade, twisted clockwork and so on), create a new antitoxin and that one does work. Kasmeer makes a portal out of the tower just in time before it crumbles to the ground.
Braham, Rox, Marjory and Kasmeer remain in the camp near the remains of the tower dealing with the roots that are still releasing toxins, and (at least Kasmeer) getting relief efforts for nearby towns going.
Kiel and Evon are still in Lion’s Arch. Evon now walks around the black lion trading post (don’t remember if he did before, I usually saw him just standing upstairs) and has a new dialogue, saying how he’s worried that now that Kiel is heavily involved in the mists and Magnus has the lionguard patroling away from Lion’s Arch that Scarlett might take the chance to attack the city (potential foreshadowing?).
Another thing I just remembered… Rox sent a mail (that didn’t go to everyone, bug maybe?) where she referred to herself as “Rox Whetstone”… maybe it means that she was finally accepted into Rytlock’s warband?.
It’s a pile of Elonian protection magic, mixed with a little monk training,
wrapped up in some crazy ritualist hoo-ha from Cantha.
A real grab bag of ‘you can’t hurt me. They’re called Guardians.
