Holy Sheeee It!
Intensely written, excellent fight scene, well done!

"
"Not exactly the way you want to head into battle," he reflected, his tone rueful.

"I dunno," offered Sternley. "It's intimidating in a straight-jacket, padded room sort of way."

"Ah, so that's the tactic then, pretend I'm nuts and the basilisk will run away in fear?"

"Why pretend?" asked Sternley and Harry offered him a cross-eyed, lopsided smile that had them both chuckling.
"
Yay for bromance in the face of certain death!

"
"You!?" he gasped, in almost theatrical surprise.

"YEAAAAARGGGHHHHHH DIIIIIIIEEEEE!" roared Harry, screaming with inarticulate rage as he burst from the confines of the cupboard, stabbing wildly with Vocerr's sword.
"
I would laugh my arse off if that's how you end things. Harry eviscerates malfoi, tosses the homunculus into some wizzy gadget that seals it in hell, and then he spends the rest of his summer with Hat (and Tom) teaching him all about the nifty magic in Rowena's tower :D
...
No?
Drat.

"
I'm already in here and let me tell you, your mind isn't big enough for three. I'd know if he were.
"
OK, well Harry, you've gone and been handed the simplest, most straight forward answer short of "Hi, I'm Tom Riddle and I'm the voice in your head", and you blew it off like... well, like you do most things :/

Freeing the Boggart, a creature which was very likely responsible for untold carnage, is such a very Harry Potter thing to do!

"
Half running, half falling, Harry collapsed through the doorway and turned to look back into the room. Just in time to see an enormous lump of brick and plaster crash down where he'd been standing a split second earlier and block the doorway.

"Well that was lucky," he shouted, through the cloud of dust and above the din.
"
See, he IS Lucky! :D

"
I'm already in here and let me tell you, your mind isn't big enough for three. I'd know if he were.
"
*facepalms* I mean, Gryffindors Charge Forward! and all that rot lol

I'm having a ton of fun!

"
Harry pulled them back on, they were cold and wet, but much cleaner. He wondered if he were being foolish, if he weren't overreacting. There wasn't anyone here to see him. There wasn't any escaping the massacred goblins in the atrium either.
...
"Normally only the muggleborns, too. Wizards don't set much stock in that sort of thing. I suppose when you grow up with miracles commonplace it doesn't really seem relevant."
"
Intriguing. Harry's 'gut' is usually spot-on, and yet your world has no 'gaia' or 'mother magic' type of cults for the wizzy world. Hmmm...

"
"You're can't be real," he said. "I destroyed the diary. You were only a memory."

"A good hypothesis," admitted Tom, walking closer to Harry, his dark eyes glittering. "Except, I can touch you now."
"
Oh... well, shite.
I mean, if Tom wanted Harry dead outright, he'd have just AK'd him in the back.
Either that, or stabbed him, conked him with a rock if nothing else. No, Tom wants Harry alive - but why, and for how long?

"
He stood for a long time, listening, his mind filtering out the sounds around him. A moment ago, he'd heard only silence, now he knew that every inch of the forest was alive and buzzing. Every sound had been amplified a hundred fold into Harry's head and his body resonated with it. The trees lit up with an unnatural red glow that flowed in the breeze like fire; every blade of grass and the leaves quivered motionlessly, humming with energy. The entire world undulated, power running through it in huge currents and every living thing swelled as though fit to burst, each poised to explode into a thousand shards of lacerating razorblades, edges keen in the dim light.
"
Very intense and definitely useful - if he can learn how to control it!

"
'Relax,' said the other voice, sounding far away. 'It's okay. It's part of you. Use it.'
...
Four thousand, eight hundred and twenty three feet to the south a fire crackled.
"
hoooboy...

"
"Now, do you reckon you might be a bit more quiet? We're trying to be stealthy
"
I am very confused why Harry and Sternley are speaking out loud when they can talk in his head... but, supposedly, stealth is paramount. Kinda lame plot fail :(

Well, the goblins have apparently decided that they aren't just going to war with the wizies, but the whole dang world. I haven't seen any reason to think their entire army couldn't be taken down by a single company of any single nation's mobile infantry. Dragons would be a trivial inconvenience to a bracket of SAM's... past that, heavy arms for the trolls and light semi-automatic weapons for everything else.

Solid stuff. I'm too lazy to look, but these names have the sound of real legends.

*WHOOOOSH!*
That was the sound of the breath I didn't realize I'd been holding!

Excellent building block chapter.

This is so fun! It has gradually shifted from an alternate universe Harry Potter Story to a Heroic Fantasy tale with Harry just happening to be the titular Hero.

"
But Harry could sense the excitement within the hat, the intrigue and the the thirst for adventure. Harry decided then that he'd clearly been a bad influence on Hogwart's sorting hat.'
"
I love it. I'm also excited that Harry can not only sense magic (and intent within) but also that Sternley is adventurous. Then again, were he not, I doubt they'd have gotten half this far! :D

"
"You have faced it before and walked away a champion. You must face it again."

Harry swallowed and nodded.

Because that could surely only mean one thing.

He would have to face a basilisk again.
"
Well, either that, or a snakeymort.

Dude... that was an amazing piece of Fantasy writing, well done!

"
A voice spoke to him in his dreams, sometimes it seemed only occasionally, but other times it seemed constant and endless, but it was always incoherent and half-heard, as though spoken from a great distance away.
"
So... is Tom only able to be heard clearly when Harry's mind is reliving... Tom killing his parents?

OK, how did he survive the cold night, and why doesn't the coldest part of the day - pre-dawn to dawn - wrack him with icy shivers? I thought perhaps he had enchanted the wolf-skin cloak to be warm, but you made no mention of it, so I'm confused.

"
While the rest of magical Europe readied for bed or war, Harry Potter was climbing up a mountain called 'the hill of peril', with a creature he couldn't identify to kill a bird she couldn't name, to rescue a talking hat.

Just another average day in the life of The Boy Who Lived then.
"
Yeah... sheesh, at this pace he'll be totally jaded before he even becomes an actual teenager lol

"
"STERNLEY, IF LISTENING TO TV AT THE DURSLEYS' HAS TAUGHT ME ANYTHING, EASTERN EUROPEANS ARE UNIVERSALLY TERRORISTS AND EVIL."
"
*chokes laughing*
I think *chuckles* that upon reflection, Harry would realize that it is more 'listening to the drizzlies watching TV', not listening to the TV itself.

"
"JUST SIX RIGHT?"
...
Harry wheeled the car away from the remaining five pursuers,
"
I'm sure someone else has bugged you with your math error... but, yeah.

"
Ten seconds later, the windscreen filled with a view of tree-tops, the car crashed down with an almighty bang and everything went dark.

A/N: So I guess Harry is finally out of the woods.
"
erm...
'the windscreen filled with a view of tree-tops'
no?
:D

WOW that was freaking amazicating!

So, you started the story by saying that it was a bit lighthearted and I got the impression that it was whimsical at least at times.
I guess we're at times.