Just did this for fun. There are probably a TON more tropes for the chars listed below, but I don't want to sink into that black hole called tvtropes ><.

Laine Alexandra Fisher:

Action Girl
Badass
Badass Longcoat
BFS: Eschaton, her mentor's final blade.
Boobs of Steel: And how... She can wield the enormous Eschaton with one hand eventually.
Beserk Button: Never threaten Patrick in front of her. Happens whenever she's close to the Drakustal Orb as well.
Disappeared Mom/Dad
Death of a Thousand Cuts: Her skill, Sure Strike.
Peek-A-Bangs
Heroes/Heroines Prefer Swords - Her preferential Lughaid. Later, Alexandra and Durandal.
Elemental Powers:
An Ice Person
Hot Chick with a Sword: Obvious.
Heroic Lineage:
Lady Of War- Still exudes grace even when cutting people into ribbons.
Leitmotif: The game's title track; "Brave Story", is also her theme song.
Hot Amazon - At nearly six feet tall, yes.
Multi-coloured eyes - Has one blue eye and one teal eye.
Lightning Bruiser - A borderline game-breaker if used properly...
Master Swords(wo)man - With the headband to match.
Ms. Fanservice: Seems to be pretty popular with the players of Enelysion.
Muscles are Meaningless
Traumatic Haircut - She cut her near waist-length hair after her mentor passed away.
The Stoic
Scars are Forever - Has two faint scars. It's easily visible when she is angry.
You Gotta Have Blue/Green Hair: Has blue-green hair.

Patrick Rolf Sidereal

Badass Bookworm
Badass Adorable
Magikarp Power
Bodyguard Crush: On Laine, despite the fact that he is celibate.
Ill Boy
Elemental Powers:
Light You Up
Shock and Awe
Playing with Fire
Glass Cannon - Boy, can he dish out damage, but down he goes if he gets hit.
Staff Chick ( male version)
Mr. FanService - So friggen' adorable. 0_o
Nice Guy- Probably the nicest guy you'll ever meet.
Break the Cutie
Parental Abandonment: Was abandoned at birth. Taken in by a clergyman later on.
Beware the Nice Ones.
The Woobie - Sometimes you just want to give him a huge hug.
Undying Loyalty - To Laine
Holy Hand Grenade - Aureola
Chaste Hero - He's a celibate monk.
Unlucky Childhood Friend - Depending on how the storyline plays out.
You Gotta Have Green Hair
Meaningful Name - Named after the Irish saint of the same name.

Cillian Allan Reiser

Achilles Heel: His resistance is pretty low, so Magic normally poses a threat to him. And Thunder.
Badass
Blade on a Stick: Prefers Lances/Spears
Deadpan Snarker: His interactions with Siglud are hilarious. And just LOOK at his usual expression.
Estrogen Brigade Bait:
Fiery Redhead: Averted, he's pretty calm actually.
Heterosexual Life Partners: With Siglud
Red Oni, Blue Oni: Blue to Siglud's Red.
Those Two Guys: With Siglud, again.
The Obi-wan: To Laine, despite their small age difference.
Undying Loyalty: To the SangReal Throne.

Siglud James Thiessaly

Achilles Heel: Same as above.
An Axe to Grind
Badass
Boisterous Bruiser/Genius Bruiser: Played to a T. He's pretty smart, too.
Dual-Wielding Weapons
Estrogen Brigade Bait: Siglud is smexy.
Hot-blooded: In contrast to the calm, serious Cillian.
Heterosexual Life Partners: With Cillian
Heroes Prefer Swords
Mighty Glacier/Lightning Bruiser: Depending on how you distribute those Orbs, he can
be either.
Mr. Fanservice
Red Oni, Blue Oni: Red to Cillian's Blue