Anguished Declaration of Love: To Rachel when she's about to sacrifice herself to defeat Gabriel. Of course, since Roku is Roku, he pretty much forgets about it much to Rachel's chagrin.
Aww, Look! They Really Do Love Each Other: Even despite their constant arguments and banters, Roku does worried about Rachel's safety, especially after she gets reverted into the Fool Arcana.
Also a platonic (what are we kidding?!) version of this with Shintaro. Although they might not be in good terms most of the times, Roku is willing to help Shintaro in need and often screams his name whenever he's in trouble; something which Shintaro also does. Even after he loses faith in him, deep down, Roku still does care about him.
Badass Adorable: He is currently the most adorable Badass protagonist in the MG universe.
Badass Bookworm: He inherited it from his mother's side. Well... Not much.
Crouching Moron, Hidden Badass
Belligerent Sexual Tension: With Rachel and possibly this with Shintaro.
Berserk Button: Do NOT hurt either his family or his friends, especially if its either Kyouhei or any of his Arcanes, and he WILL kick your ass HARD!
Beware The Nice Ones: A staple of MG's protagonist very well.
Book Dumb: Though not actually an idiot, he is pretty much smart but he is more naive though.
Break The Cutie: Roku is pretty much prone into this, starting with Ruri went into a comatose after breaking her contract with Xerxes in Gabriel arc, losing Kakeru into the Alternate World at the end of The Forbidden Arcana arc, had his dad died protecting him from Barbatos' attack and gets Mind Rape by the Big Bad of Next Generation in Syphon arc. This is all to indicate that Next Generation-Revenant Night saga is a lot darker than the Fairytales series.
Roku also has a real nasty one in New Chronicles involving the sudden betrayal of the Mekakushi Dan that nearly killed him and Xerxes eventually in him losing faith on them.
Chaste Hero: Though he does aware of Rachel's affection for him but he doesn't really get romance in any way. Justified he's 13 by that time.
Chronic Hero Syndrome
Cool Sword: Gains Fragarach in Next Generation Season 3 and onwards.
Heroes Prefers Swords
BFS: Gains one in his Junction form with Rachel as Nero.
Dangerous Forbidden Technique: God's Judgment.
Fusion Dance: Junction does this with both of his Arcanes.
Improbable Aiming Skills: Thanks to Railgun. He manages to take it Up To Eleven than Satoshi himself.
Improbable Weapon User: Coins whenever using Railgun.
Magical Eye: The Six Paths of Reincarnation.
Master of Illusion: The First Path allows him to do this.
Reality Warper: Origin Seal.
Shock And Awe
Covert Pervert: He enjoys making Hibiya crossdressing, even with force if it have to. Everyone tends to call him out of this.
Cuteness Proximity: Like Mother Like Son. He goes like this seeing boys crossdressing, especially with Hibiya of ALL people!
Dark And Troubled Past
Deadpan Snarker: He inherits Sora's snarky remarks whenever his friends do something ridiculous, mostly with Shintaro, whenever the latter breaks out of his Only Sane Man status.
Declaration of Protection: To Rachel when she reverts back into the Fool Arcana.
Deuteragonist: Of Revenant Night. Then again... he tends to take away the spotlight though...
Easily Forgiven: After the Mekakushi Dan's sudden betrayal, Roku willingly forgives both Mary and Seto since he knows that both of them doesn't want to betray their close friends and it would out of character of them to do so.
He also does this to Reflet and later Xehanort near the end of New Chronicles.
Shintaro seems to add into this group as well by Revenant Night.
Expy: Has spiky hair and blue eyes? Check. A Friendship Freak? Check. Capable to withstand any attacks that otherwised would kill him? Check. Oblivious to Love? Check. And Practically a Forgiveful Person? Double Check. He is pretty much a younger version of Roku in School-Side Chronicles.
Future Me Scares Me: Though, it's more of an Alternate Me Scares Me, where in the "Bad End" timeline, he was possessed by Kuroha and forced to kill his friends and Shintaro.
Get A Hold Of Yourself, Man!: Often times does this to Shintaro, especially in Battle of Arcanas arc and Dark Haze arc. He also does this to Xerxes in Gabriel arc, regarding Ruri in comatose after breaking her contract with him.
Heroic BSOD: He gets pretty much of these... though he gets better by a second.
Probably the most twisted one is after his father is killed and after The Reveal of said father being possessed by the Big Bad and getting Mind Rape as a result.
And later, when he sees Riddle taking out Ryoko's soul.
He also had a real worst one in New Chronicles, with Xerxes nearly dying as a result of Taking The Bullet and losing his faith to the Mekakushi Dan after their betrayal.
Ho Yay: See Even The Guys Want Him above.
Idiot Hero: He is technically not an idiot but he has his moments.
If It's You, It's Okay: Towards Kakeru, apparently. In New Chronicles, it seems he's one to Shintaro.
The Kirk: To Shintaro's McCoy and Kakeru's Spock.
Laser-Guided Amnesia: Due to his Origin Seal activated, he doesn't remember that he was a Contractor all along. Or how he nearly died or even having the God's Judgment ability.
Let Them Die Happy: At the end of New Chronicles, along with Keith's help, Roku eases Xehanort's pain by reuniting him with his dead son just before he died.
Manic Pixie Dream Guy: To Kakeru. He succeeds, sort of. He also ends up being this towards Shintaro, despite not being one, as told by Ene.
Mind Rape: Gets into one during the Syphon arc by Riddle.
Mismatched Eyes: Like his mother, his left eye turns red whenever activating his Six Paths of Reincarnation.
Mistress And Servant Boy: His relationship with Rachel, which is ironic considering that he is her Contractor.
Morality Pet: For Xerxes and Mukuro.
Near-Death Experience: Like all the members of the Club, Roku nearly died as a result of using his God's Judgment ability to kill of the bandit that tries to kill Ruki and later on using it again to save Shintaro. Both of these events are what activates his Akasha Seal.