I am not Mr. Wizard and Carlos isn't Jimmy

I am not Batman, neither Thomas nor Carlos are Robin the Boy Wonder, Molly isn't Batgirl, Ebeneezer isn't the Commissioner, my Lab isn't the Batcave, the BlueBeetle is not the Batmobile, my blasting rod is not a Batarang, Bob isn't Alfred, Lara isn't Catwoman,  and Mouse isn't the Bat-Hound.

or something about the hot tub

One of the best ones is "If I wished to kill you, my host, your blood would be seeping from your broken corpse and mixing with the rain on the sidewalk"

But that's a little over the top for a tshirt.

But having him hold them off with a cross while yelling "YOU. SHALL NOT PASS!" is not ok.

When Molly is studying for finals, I am totally NOT allowed to look grave, get her to ask what's wrong, and say "You.  Shall Not.  Pass."

To add my 2 cents:

Look with deep suspicion on anything you put in just because the reader needs to know it.  As the author, you need to know it.  Your main character might not need to know it, most of the people he's bugging with questions might not need to know it, and the character who DOES know it will act on that knowledge and let it leak somehow or another.

On the opposite hand, don't keep secrets about what the POV character thinks he's doing.  If he's sitting around drinking because he's trying not to think about how he just was dumped, that's what he's thinking about and it should at least be hinted at. 

So from this argument, you could open with a lot of description of messy apartment, beer cans, and the guy opening another one and pretending he's just watching TV while you clue in the reader with some line like "I hadn't watched the Friday lineup for months, since Sue always wanted to go barhopping on Friday - let's not think about Sue."  But pretty soon you need to introduce the current problem that he's going to start dealing with.

If the problem is that he's in the witness protection program and his cover is right now being blown you do NOT have to open with any history about that.  He's sitting there trying not to think about Sue when there are gunshots in the street and he reacts from what he already knows - and he'll be explaining things by his assumptions.

To black out just the city - and be spooky -

One set of ideas, for actually preventing the light from getting there:

1) Light bending field effect that distributes the sunlight elsewhere.
2) Invisible Sunlight eating monsters floating above the city
3) The city has somehow become repulsive/super reflective to sunlight (very similar to 1 but the magic has been cast on 'the city' rather than 'above the city')

Spooky ways to have the populace see no sunlight

4) Illusion that sunlight does not exist has been cast upon people in the city.  Their plants, pets, etc have no such problem.  Then there's the question of whether their disbelief in sunlight leads to protection from sunburn, etc.
5) Experimental Protection spell has been misapplied and the people are now protected from sunlight, direct or reflected.

Unless they're hot.  Gigidy-gigidy 

(sorry, it had to be done)

Is there something burning around here? Shall we try out the water gun of extreme disgust, with garlic.

Harry is also not allowed to randomly squirt Thomas with garlic water just in case a Black Court vampire has got to him.

To get back on topic:

Next time a baddie chains him up, Harry cannot offer to connect him up with the Handcuffs of the Month Club.
Or say, "Thorn Bracelets?  Hey, thanks, just 2 more sets and I'll be able to tie up the whole White Council."