Thad adapts quickly to the time periods / earths he's left in. Often using or stealing accomplishments and knowledge that don't exist yet to succeed and help himself. Bringing in or reconstructing future technology. 

Thad created fake trails to throw Team flash and others off, hiding himself for a couple of weeks. 

Before coming to the present Thad never actually interacted with a female.

He isn't comfortable hiding in a crowd. He would feel overwhelmed and like he is suffocating. He would run out immediately. He has extreme difficulty in social settings.

Thad can't really blend, and has a rather...unique style. Which he stole from stores.  And later on bought for by his team.

Approval is something incredible dire to him. Especially from parental substitutes or significant others.

He never heard someone say I love you to him. His father gave the illusion of care. leaving him alone some of his life with nothing but a computer for company.

He antagonizes heroes so they would go after him. Provoking them and pushing them to the edge. Unconsciously so they can stop him from killing Nora/ what his father designed him to do. Picking fights but when they refuse to take the bait, to fight a child he leaves. Unable to comprehend the good in their actions.

He watches Nora and Team Flash constantly. Watching, partially and fully obsessing over them or random heroes.

Does not think positively of himself, the problem grew worse after his redemption.

Some of his more sadistic actions weren't his fathers orders or even part of his plan. His acts of disobedience, his excuse to go after and attack people. He accepted the blame for his actions, and owned up them. Forgiving himself after some time it haunted him. But becoming too much like Barry when pinning down responsibility. 

Sings like Barry, but is private about it. Loves musicals, and certain scenes..

Uses the word "Shway" only in his head. But curses with future and present  slang such as Shrap (shit) and Shock (Fuck) out loud all the time. Snapping at people with the worst language to see their disgusted reaction. 

He has no idea how to act like a teenager. Realistically act like one or talk like he is normal. Imitating someone else is however within his skill set.

Hates his reflection. When he looks at the surface all he sees are the labels he's been given or someone lost, struggling to define himself.

Draws attention to himself for conflict or approval.

Unspecified disorders and abuse as a result of his upbringing. After trying to be better, he blames every negative trait on his father claiming that without him he would've been the best version of himself and undamaged. Eobard put significant doubt on that idea  saying some of it is just genetics, his own flaws. Thad doesn't know what could be true.

Considers himself the abomination  amalgam of his family tree.

His speed is so much of his identity, if he lost it he would never be the same. If he was 'cured.' He wouldn't be grateful. He would do anything to get it back.

He does enjoy hurting people like Eobard. There's no excise for that, and he knows it. He inherited that from his father. He does want to hid the dark impulses, to pretend he can rise above it. But doubts it would ever happen.

He wants to have his own personal flashpoint in which Nora raised him. Where he wasn't damaged, and always had family. But he knows he can't play god, and he can't risk it. Promising to be the one not to change the timeline.*

If he could just spend one afternoon at Jitters with Nora, he could die happy.

He's gone over everything in Nora's journal. Unlike speedsters he doesn't lose the knowledge he absorbs when he speed reads.

He is the only known speedster with green lightning. It's a mystery he doesn't understand, how green came from a history of yellow, red, and purple lightning. Or the inherited speed force connection.

He hates what he sees when he looks in the mirror. He's been known to shattering the mirror and pick up the glass shards.

He visits the Time Vault ( Eobard Thawne's secret room.) and occasionally sleeps there.

Expects the worst from everybody and doesn't have high hopes for their treatment of him.
Eobard has broken and scarred him on the inside and out. So he doesn't react that much to his own pain.

He is protective of Nora, extremely protective.

He considered Ralph a fool, then a friend and finally a coach. 

Doesn't consider himself a member of the West-Allens. At first.

Follows the West-Allens constantly similar to what Nora did. Only he doesn't draw attention to himself or talk to them.

Sadistic impulses, and loves using his power to fight, to break. Likes to rub it in people's face when he takes someone from them.

Scared by a certain member of Team Arrow.

One of his greatest fears is Cecile picking up on his thoughts and learning everything about him.

Cisco constantly compares and calls him Malfoy due to Thad's attitude, hair color, and his preference of wearing black and green. After learning upon Thad's parentage, and upbringing he compared him to Anakin, Loki, Daken, Starscream . Thad's constantly glaring after the comparisons.  Post changes it has not ended, the list growing linger, Tommy Oliver, Artemis Fowl, Eustance Scrub. Chester chiming in with Kylo Ren. The list kept growing

 Killer Frost nicknamed him Dexter. It's unclear if she means the cartoon character or the serial killer character or both of them.And then calling him Kline because of his gold eyes. 

He hates it the fact that his father left Star Labs to Barry, and that he gave more affection towards everyone he manipulated. Of the people he treated like sons.

He's known for a few public meltdowns in and out of costume

He eats when he's anxious, and stressed which is constantly. He uses his speed to hide the evidence constantly.

He sleeps at Star Labs, gaining every meal from Jitters and Big Belly Burger... The team didn't pick up on that for a while.

Sits at the end of the table whenever he's at a family dinner, always shy, staring down at his plate.

He hates it when people try to exclude him because of his age.

PDA makes him freeze like a deer in headlights.

Originally dismissive and private of music, until he listened to the song Gasoline and realized it was a perfect fit to him. After that he constantly looked for more songs that fit him.

He found a way to broadcast music to himself so that he can listen while being faster than regular sound.

Subtly and not so subtly hinted to Nora that he's her child.. His interest in Nora was once misinterpreted as a crush, Thad's reaction was pure revulsion

He hates it when someone has to pose as his parents or family..

The Team sent a file on him towards ARGUS as a precaution early on, meaning there is a special cell waiting for him and countermeasures.

Hates it when people think he's a fan of Quicksilver.

Thad has a few aliases, and fake ID's. Wallace Sans Souci, Tommy Shepard, Daniel West, Bar Torr, and Mitch Grayson are the only ones known.. . Never keeping all of them on him at the same time.

Refuses Ralph's advice but had to admit the Elongated Man was right.

If a DNA test was run Thad would freak out trying to ruin the results.

Has mixed mostly violent reaction when people calls him son.

Would cheat in a race with another speedster. Using every trick imaginable and would admit it.  Cheating at other games as well.

He hates it when people reject their own powers and act afraid. " YOUR THE IMPOSSIBLE DEAL WITH IT." Coaching them through it, answering every question while very frustrated and annoyed with it.

Watching movies with him results in him complaining about everything unrealistic in it, and laughing during the especially bloody and violent parts.

Agreed to a interview with the one reporter he respects enough to get it right. Lois Lane.

Thad still doesn't understand why Cisco chose to stop being Vibe. Not even pretending to accept his decision.

The negative speed force is part of the reason Thad has trouble understanding others.

Switching from the speed force to the negative speed force leaves Thad more than a little shaken. Nosebleeds, losing his restraint.. Increasing how prone he is to violence.

Whenever he's been underestimated, humiliated he plans his payback meticulously.

After nearly losing an eye thanks to The Earth X Oliver Queen Thad started wearing goggles to protect himself. Eventually making an advanced pair with an A.I. inside.

He hates Iris's cooking especially her breakfast. So he started making his own.

He's cold and condescending to new members of team flash. But warms up to them slowly.

Despite being proud originally to be a Thawne he has no respect towards his late ancestor Eddie. Calling his sacrifice pointless.

Thad makes cruel, comments that goes too far to mock others or to joke. The worst kinds of things to drive someone to tears or over the edge. Things that when he looks back on he feels as disgusted as anyone who heard it. For example. " Take some notes before you die Oliver Queen." "Just as Easily wiped out as the JSA."

Thad created a way to change the color of his lightning for pure cosmetic reasons. An illusion put up by his suit. Such as changing the green yellow to try and pass as Barry. Or to hide it when his lightning turns blue out of velocity nine use or red due to the negative speed force.

When he has time for himself. From an entire day to just an afternoon or an hour and a half. Thad travels, not for the sights just to read about the history and indulge of the culture or at at least. If he's brushing off crumbs or something off his shirt, he'll say he just grabbed something.

Thanks to other timelines where Barry married someone else or at least where an alternate version of Barry had children with someone that wasn't Iris Thad technically has a few aunts and uncles. Some of which are close to his age.

Thad isn't an X-Men fan. He's especially annoyed by the timeline travel used, and all sides shown in it. But he hates the Von Struckers. The Fenris Twins disgusted by those characters.

He can't handle rejection well. If he tried to join someone, or a team and be rejected, turned in he wouldn't be forgiving.