Sirius stood up paled faced at hearing that voice and almost fainted. Both Harry and him follow the voice until they stood face to face with his mother portrait
"Hello dear mother, so haapy to see you" said Sirius trying and failing to lift the portrait
"Walburga" said Harry with a nod
"I have not given you the liberty to call me by name yet brat. Who are you?"
"Well you did, we spent so much time together at one time, planning, plotting, celebrating me killing a few people... but that's the past, or the future? I don't know anymore, my name is Hadrian James Potter madam."
"WHAT?" Said Sirius, "Ohh really? A time traveler? And who did we kill?"
"Yup, you helped me kill my wife, one of her brothers and her mother, the Weasley. They had me potioned to the gills, you made me go to the goblins to flush it out of my system and helped me make it look like an accident, like it was revenge for me killing the dork lord a second time in my teens. Aand speaking of killing, Kreacher!"
"Yes master?"
"I need the locket" and Kreacher look at Harry with hopeful eyes, so he lifted the locket from his neck and gave it to Harry, who left it on the floor and with his hand outstretched he called out his Zanpakuto plunging the tip against it, making a shade leave the locket wailing swinging again against the shade it exploded in a puff of smoke.
"Oh thank you master, you completed master regulus wish Kreacher could not."
"That's it? Snakeface is dead pup?"
"Oh no, the mother fucker made 6 of those. Sick bastard if there ever was one."
"Merlin that's bad. But you already know where they are right?"
"Yup, already destroyed 2, one was in my scar which is healing now, the others are Ravenclaw's Diadem, his diary when he went to Hogwarts, Huffelpuff Cup, and The ring with The Resurrection Stone, he made a 7th that was his snake familiar much later."
"Lord Voldemort never went to Hogwarts."
"Not with that made up name Walburga, his attended with his real name, Tom Marvolo Riddle which if you move the letters you get I AM LORD VOLDEMORT. He couldn't have people question his quest for blood purity with people knowing he was the son of a Squib and Muggle." and Harry did the flaming letters thing with his wand to show Sirius and the portrait of the old woman.
"I can't believe it! The dark lord the champion of purebloods son of a muggle AHHAHAHAHA." Sirius laughed so hard he turned into a dog
Walburga was scowling so bad her lip might just fall of the portait, but to finish putting the proverbial nail in the coffin he told her "Also all that crap about him being the Heir of Slytherin was a lie, there's thousands of Parseltongue speakers across the world, just that as I said earlier Britain Wizarding community is so fucking closed up that they don't even know and as people are sheep here they believe the first thing someone says. He tried to claim the Slytherin lordship but was denied. Her mother was from the Gaunt family and that family always claimed that they where descendants from Salazar Slytherin but none of them could ever claim it and a lot of them died trying, that's why they lived in so much poverty."
A few hours pass till Sirius calmed himself, he was changing between animagus and person every other minute from laugh. When he calmed down, Harry made him lie down on his bed and started healing him with Kaido.
Now that he was better Harry said "Ok snuffles, it's time to start planning your freedom. We've got 2 choices. Number 1) I lift the illusion of you on your cell, and we wait a couple of days to go to the ICW with the rat, you turn yourself in get a trial and you are free as a bird. Or the much more devious and destructive
Number 2) I keep the illusion, put the rat on stasis and we wait, in my time they didn't release you from there you had to escape after 12 years because someone got you a newspaper and you saw on a photo that they Weasley where keeping a pet rat, aand after a few years you turn yourself in demand the trail and you cash in a good amount of galeons from the ministry for illegal imprisonment. Aaalso if I'm not mistaken, cousin Lucy is sometimes using the black vault at Gringotts to loan some money to his death eater buddies, which you can then later cash all in with interest of course maybe leave them paupers, who knows."
"Bloody Slytherin! Are you sure you are not the real heir pup?? Number 2 obviously number 2"
"Okay then, let's have dinner and tomorrow we go to Gringotts I. Dumbledore's been dipping into my trust vault because he named himself my magical guardian and he cant enter the main vault because he's not a Potter"