Arch-Enemy: Omarosa. Initially he just started the feud because he knew that Trump would try to keep her in the competition as long as possible, and that if there was a feud between them he'd also try to keep that going as well. However, she escalated it to levels that even Piers (and Trump) didn't expect.
The Bad Guy Wins: Trump specifically put him in the final because he wanted to set up a "Good vs. Evil" fight between him and Trace, the "good" part of that match-up. Piers won, though admittedly for pretty legitimate reasons given how much more money he raised than Trace.
Achilles' Heel: The main thing that brought him down was the fact that he failed to anticipate how important donors would be, and so was never able to have them available when he needed them. This was something he made sure not to repeat when he came back for the All-Star season.
Badass Baritone: Something that he frequently took advantage of, especially when narrating the voiceover for the team's Week 2 advert.
Crouching Moron, Hidden Badass: She did horribly in the first four tasks, but then steered her team to a resounding victory in the Week 5 task, and never looked back. Many fans still feel that she should have won this season, and got screwed out of being in the finale thanks to Trump wanting to set up the battle between Piers and Trace.
Only Sane Woman: Aside from Marilu, she was the only woman who ever really looked like a contender.
Nice Guy: Among the men's team, he was probably the one with the nicest, most level-headed personality.
True Companions: With Piers, despite their very dissimilar personalities, likely because they already knew each other before the show and were the only two non-Americans in the cast (aside from Nadia, who was fired very early on without ever being on the same team as them).
Arch-Enemy: He saw Piers as this from Week 5 onwards, though Piers was too busy feuding with Omarosa to really care.
Moral Guardians: Decided to appoint himself as this in the Week 8 task, and browbeat project manager Tito into not making their advert overly sexy. Said advert promptly lost the task after it was deemed to be too boring.
Epic Fail: Lost three times as project manager, and the third occasion resulted in the biggest defeat in the show's history, and Omarosa being fired.
Moral Event Horizon: Trump himself had to admit that her insulting Piers's children was this, and that he would have fired her had their team not won that week.invoked
Never My Fault: After the women's team got thrashed in the first task as a direct result of her ordering them not to bring in celebrity contacts, Omarosa's response in the boardroom was effectively "Well, of course it's the rest of my team's fault, they should have know I've got no idea what I'm talking about!"
Xanatos Sucker: Didn't see anything suspicious about Omarosa suddenly backing out of the project manager's role after Trump announced that the losing project manager would automatically be fired that week, nor her successfully coercing him into taking the job.
Butt-Monkey: While she was one of only two women (the other being Carol) who seemed to have any clue, absolutely nothing went right for her in this season. She was on the losing team in all but one task, lost twice as project manager, and got fired after the second such occasion.
The Cassandra: During the first task she actually worked out almost as quickly as Gene did that they should bring in large donations from rich contacts, only for Omarosa to tell her that was a stupid idea, and that they should just sell to the public. They duly lost, with only the fact that Marilu (and Jennie) decided to ignore Omarosa's instructions and brought in contacts anyway preventing the women getting outsold by a factor of 10:1.
Karma Houdini: She screwed up a meeting with Kodak in the third task, which resulted directly in her team's defeat. For some bizarre reason however, Gene refused to bring her back despite Trump outright telling him to do so.
No Social Skills: During what was supposed to be a fact-finding meeting with some Kodak executives, she spent nearly the entire meeting talking about her ideas for the advertising campaign rather than actually finding out what she was supposed to be advertising. Then, when Trump mentioned the incident in passing three episodes later, she blew up at him for not letting the matter go, which resulted directly in her being fired.
Screw This, I'm Outta Here!: After the spying fiasco in Week 5, he quit the show during the initial boardroom, saying that he'd already made a decent amount of money for his charity, and that staying on the show wouldn't be worth the stress it would cause him.
We Used to Be Friends: One of the fastest examples in history. In Week 4, he openly called Piers his MVP in the pre-result meeting with Trump. In Week 5, he gave Trump a "Piers goes or I go ultimatum" during the boardroom (though ended up rendering the matter irrelevant by deciding he wanted out anyway).
Sacrificial Lamb: She was the third and final member of the women's team who got the axe early on for being too low-key and not really contributing anything.
Genre Savvy: He was the first person to work out that the way to win tasks wasn't just to upsell things, but bring in huge donations from rich contacts.
Suicide by Cop: Refused to admit that his team's marketing campaign was off-base in Week 3, and so deliberately brought back Omarosa and Jennie, neither of whom were responsible for the loss, so that Trump would have to fire him.
Worthy Rival: Piers saw him as this, admitting that had he not hit the self-destruct button when he did, his contacts list, business brain and decades of media experience would have made him an extremely potent competitor.
The Generic Girl: Granted, she probably wasn't helped by only knowing English as a second language, but she made probably the least impression of all the candidates this season.
Sacrificial Lamb: Up against Omarosa (who Trump was never going to fire in the first week) and Carol (probably the most famous member of the team), she really didn't have a prayer of survival.
Tragic Mistake: Thinking that she could keep Hugh Hefner in reserve and wait until she was project manager before getting him to bring in a donation. Granted, it would have made no difference to the result unless he donated $50,000 or more, but it got her fired nonetheless.