Depressingly lampshaded by Kurt in The Harpy when he tells his mom he has to remind Blaine that "he is in fact his boyfriend and not his liege lord" to which Blaine always gives him confused Puppy-Dog Eyes. So yeah, Kurt sees the Courtly in Courtly Love in-universe apparently.
Broken Ace: Played With. Blaine is obviously type two, but he's literally an ace who got broken. His chivalric tendencies are overcompensation for his regrets and low self-esteem.
Broken Tears: At the end of The Red Bull. He's stressed out, concussed, and he's barely aware of what's going on.
Deconstruction: And how. Blaine is Kurt's Knight in Shining Armor because 1) he's sheltered and naive enough to think that's how the world works, 2) his family is barely functioning, and 3) his first relationship ended horribly.
The Champion: For Kurt. Blaine also has a host of champions in the Warblers and Greg, due to his sheltered nature.
Cool Big SisandBrother: Blaine's siblings Kyle and Lydia are respectively a photographer and an art student studying in California, and have a much better relationship with Blaine than their parents do. Then again, it doesn't do much good since they're not home very often.
Courtly Love: A depressing take on Kurt and Blaine's But Not Too Gay portrayal. Kurt's not too enthusiastic on the matter of sex, but Blaine takes it really far. And he has a reason.
Dude Magnet: Blaine is a toned-down example with "only" two guys on his record plus one he doesn't know about, but he makes it up in sadness and terror.
Blaine's attractiveness is lampshaded in Robin Hood when Morgan asks if the Warblers know anyone Reid might look like. (Blaine mistook him for his first and refused to talk to him.)
Trent: How many unrequited loves can Blaine possibly have wandering around town?
Thad: Are we counting guys and girls?
Exact Words: "I've never been anyone's boyfriend." The story behind it is just as depressing as it sounds.
Extreme Doormat: Played for Drama—due to emotional issues and loneliness, he's very obliging. The Warblers call Blaine Kurt's bitch, and Sarah notes that Blaine's unusually passive.
Lonely Rich Kid: Rich enough to live in a mansion with two home theaters (one for him and one for his sister). However, his father is outright neglectful, and his mother is extremely traditional. His siblings care a lot about him, but aren't physically there due to work/college. It's implied this is why he's so sheltered.
Oblivious to Love: Taken to the logical (and Fridge Horror) conclusion: If Blaine takes months to realize that Kurt fell in love with him at first note, he wouldn't have any more of a clue that he has a stalker.
Too Dumb to Live: Lampshaded heavily by the Warblers. However, it's played for drama/tragedy since Blaine's not technically stupid—he's just emotionally damaged and idealistic enough to make poor choices.
True Companions: With all of the Warblers in general, but especially with Wes and David.
Wide-Eyed Idealist: Yep. He's ridiculously trusting and naive. The Warblers frequently compare him to a puppy.
A temporary member of the Warblers, and currently back at McKinley High. Mostly the same as his canon-persona, though with a few additional twists.
Berserk Button: He may be a slender, youthful choir-member, but it's very ill-advised to kidnap his boyfriend. Don't try to strangle Kurt either, because he'll go ballistic and start pummeling you.
Cry into Chest: With Blaine in The Midnight Carnival. Then Blaine cries into Kurt's chest in the The Clock.
Abduction Is Love: He kidnaps Blaine, and gets forced to kidnap Wes and David along with him when they refuse to leave Blaine alone.
Knight of Cerebus: There are hints of this starting from his mention in the thirteenth chapter, but come the nineteenth chapter, there's a huge downswing in the Warblers' exaggerated comedy.
Nice Job Breaking It, Hero: Congratulations! You kidnapped your crush, along with his two best friends, using his own car! You also accidentally concussed him, so he's not only terrified of you, he's not making a whit of sense! You have now committed at least three crimes in one day!
Understatement: He says that he "lost his temper" when trying to strangle Kurt.
Unreliable Narrator: For someone whose introduction was so sugary, his actions are a huge contrast.
Walking Spoiler: Doesn't appear till the thirteenth chapter, and doesn't do anything major until the nineteenth.
Wrong Genre Savvy: Seems to think he's the Dogged Nice Guy who'll end up with Blaine after he breaks up with his selfish boyfriend Kurt. He's actually a random guy obsessed enough to stalk a seventeen-year-old, and said teenager probably has no clue who he even is.
Gregory "Greg" Morgan
The Anderson's house manager and fifty-three years old. Loyal, laid-back, and rather paternal towards Blaine. And he's also a spy.
Parental Substitute: He immediately starts looking for Blaine after he, Wes, and David get kidnapped and Blaine's call home devolves into incoherent crying.
Sarah suggests that Blaine should tell Greg what happened with his almost-boyfriend. Blaine's reaction (paraphrased, it was 'Oh God no, he'd kill me') implies that Greg has basically become the closest thing he's got to an actual father.
"The Reason You Suck" Speech: Gives one to Luke when he finds out that Blaine got kidnapped and Luke's first reaction isn't to freak out or ask what's happened, it's to berate Greg for not telling him earlier.
Dalton's choir group. There are twenty-two of them besides Blaine and Kurt. The named Warblers in canon are Jeff, Nick, Thad, Trent, Wes, and David. These guys are the main source of comic-relief and heartwarming moments in an otherwise soul-crushing story.
Character Development: Inevitable, since they were minor characters in canon. Nick is a foul-mouthed stoner, Wes and David are Blaine's overprotective best friends, they take everything very seriously, and they're all as close-knit as the New Directions.
Chekhov's Gag: The Warbler's buddy-system on finding out about Blaine's stalker is a little over-reactive, but justified. If Wes and David hadn't been with Blaine on the last day of school, he'd have gotten kidnapped by Alex without anyone to help.
Chekhov's Gun: All the tracking devices that they use for Shipper on Deck gags? Very handy when David's cuff-links record Wes, David, and Blaine's kidnapping.
Chekhov's Skill: David writes everything down. Leading him to realize that the same guy's been following Blaine around for a while.
Crazy-Prepared: Hoo boy. They're Genre Savvy as hell, their list of Zany Schemes to keep Kurt and Blaine together went from A to M (and later moved on to numbers), they have a first-aid kit, and they have a host of recording devices. They also have a lot of secret/emergency Warbler meetings in response to events.
The Power of Friendship / True Companions: They'll rip your kneecaps out if you show any sign of hurting Blaine or Kurt, and they drag their members to therapy on an annual basis. They'll also tell a staff member as soon as they find out one of their members is getting stalked, and then help with the police search once they realize three members got kidnapped.
Serious Business: Part of the reason they're so Crazy-Prepared is because they take everything seriously, ranging from bets, rehearsals, emotional breakdowns, and stalking.
Shipper on Deck: For Kurt and Blaine, as well as two of their past members. They're also betting on Jeff and Nick.
Those Two Guys: Jeff and Nick. Wes and David are also this when they're not with Blaine.
Vitriolic Best Buds: They constantly mock Blaine for being stupid, chivalrous, and using too much hair-gel, but they do genuinely care about him and are very protective. They also tease Nick for being a stoner.
A Filipino-Hawaiian member of the Warblers, with a girlfriend called Lacey. Part of the Warbler's council, and one of Blaine's best friends.
The Bet: Has an uncanny ability to win any bet he makes. Nick calls it his "magical Asian gambling", and the other Warblers joke about how he sells parts of his soul to the Devil every time he makes a bet.
Hidden Depths: He writes urban fantasy stories about old-school unicorns.
I Call It Vera: His gavel is Marcus. He's also trained the Warblers to respond immediately to the sound of a gavel.
Mundane Utility: He has considerable skill with cameras, but the most he does is record Kurt and Blaine so the Warblers can validate their many, many bets, plus embarrass them on Facebook and blackmail them for homework help. Speaking of bets, he uses his ability to win them to solve Warbler drama.
The Nicknamer: Sometimes calls Blaine "little hapa" out of fellow-feeling (he and Blaine both have Filipino mothers who are very traditional).
The Stoic: Shows exceptionally after he's locked in Alex's basement with Blaine and David. Blaine is falling apart due to his concussion and David is understandably livid, but Wes just grabs his phone and tells Greg as much as he can.
Not So Stoic: In Maid Marian, he starts crying when talking to his dad.
Dark and Troubled Past: When Morgan and Rossi question him, we find that his parents divorced when he was eight, and he moved in with his aunt after coming out as bi to his less-than-informed mother a year ago. He also tells Jeff that sometimes he smokes because Jeff overwhelms him.
Hot-Blooded: "We need to find that bastard and rip his fucking kneecaps out!"