Not So Weak: In the first book it's much more obvious, but she does keep many of the same character traits. It's also apparently a useful set of characteristics for wizards in general, who aren't really supposed to do things for their own benefit.
Little Miss Snarker: Mostly before Roshaun disappears. After that, she doesn't seem to take as much pleasure in it, and it has a far darker tone.
Mama Bear: Towards her "buddies," a race of sentient silicon lifeforms she helped "birth" — since they came into existence, all the Bad Guy has to do is suggest a threat toward them and said Bad Guy will immediately suffer The Wrath of Dairine
Playful Hacker: Described as one in her debut as a protagonist, but this is dropped afterwards apart from being good with computers.
Ship Tease: No one is quite sure what is going on between her and Roshaun.
Overprotective Dad: Well, as overprotective as he can be, considering that his children can rewrite reality.
Badass Normal: She starts participating in the fighting aspects plot around the eighth book despite not being a wizard. However, she is a natural in The Speech and so she can order alien tech from their version of the internet.
Cunning Linguist: A natural in the Speech and other languages, including long-dead Martian writings that had Wizards stumped.
Aloof Big Brother: To the other Powers; the Lone One is frequently known as "Eldest, Fairest and Fallen".
Big Bad: all minor villains answer to It one way or another; more to the point, It is implied to be at least partly responsible for all the evil in the universe.
Black Sheep: The Powers That Be kicked It out for inventing entropy and death.
Body Surf: Appears in lots of bodies over the course of the series, sometimes possessing mortals, sometimes as an aspect of Itself.
Cain and Abel: A variation with multiple Abels, since the Powers are more or less siblings.
Demonic Possession: has the ability, but it is very difficult to use effectively, especially on a wizard.
Don't You Dare Pity Me!: To Dairine in book 3 and this pity leads to an aspect of itself accepting forgiveness and returning to Time Heart.
Evil Redhead: Appears in different bodies and doesn't look the same to everyone, but Nita usually sees It as a man with red-gold hair.
Evil Plan: It's always offering Its "Gift" and spreading it around the universe, though the reasons why vary based on specific aspect the wizards are dealing with. In some cases the Power is a proud inventor, in others It's genuinely malicious, and in others It thinks It's being helpful.
Heel-Face Turn: In ''High Wizardry" Dairine convinces an aspect of the Lone One to redeem itself and return home. There are other aspects causing trouble but this is a good step in the right direction.
Fiery Redhead: The Lone Power is pretty hot-tempered and he appears as a redheaded guy— Nita sees him that way, at least, in SYWTBAW and High Wizardry.
Fighting a Shadow: Every aspect that Nina and Kit fight is an aspect of it, not the real deal.
I Have Many Names: The Lone Power, the Starsnuffer, the Old Serpent, the Isolate, Esemeli...
Light Is Not Good: Back before it was cast out, it was the fairest and brightest of the Powers That Be. It's contribution when the universe was created was entropy and death.
Man Behind the Man: Prefers this tactic, although when dealing with wizards it is often forced to come out into the open.
Barrier Maiden: A Spear Counterpart version. He is a Font of The One's power, I.E. the means by which Nina, Kit, etc receive their power. If he realizes it, he'll die, so everyone is very careful about preserving the Masquerade.
Deadpan Snarker: Again, only in the last book or so— Wizards At War, arguably, and A Wizard Of Mars, definitely.
Neurodiversity Is Supernatural: In A Wizard Alone, Darryl becomes autistic in an attempt to withdraw from the sensations of being malignantly observed by the Lone Power.
The Rainman: Though his autism is bizarrely portrayed (his behaviour on the outside is accurate enough, but his experience from the inside not so much), Darryl makes his first appearance as a severely autistic boy who also turns out to be a human conduit for a large amount of the wizardly power available to Earth. Justified Trope: Darryl's autism is something the Lone Power has done to him; it's reasonable that it would only superficially resemble an organic condition. So in other words, it's not really autism.
What Beautiful Eyes: Darryl, who has eyes so innocent that it hurts the first time you see them.
God Is Good: An Incarnation of The One and a fantastic pet. He's been working on some Powers level scheme all this time.
King of All Cosmos: He's the local God, and his favorite pastime is to incarnate as a dog because he likes the 'spell it backwards joke'. According to the Transcendent Pig, He has fondness for bad old jokes.
Uplifted Animal: At first thought to be because of exposure to wizardry, but his high intelligence is actually because He's The One.
Rule of Three: Claims to have the 'three things' rule because wizards can get into a lot of trouble with just one response.
All Therapists Are Muggles: Subverted. While not a wizard himself, he's in on The Masquerade and knows how to spot one. This comes in handy when the cast needs time off from school to save the universe.