"I guess there really is no point in wasting time and I might as well get right to it." Logan said before he jumped right off the edge of a cliff into a sea that was completely black, with raging waves and stormy weather that would easily capsizes a boat and her crew who were foolish enough to sail out in such a sea.
Logan instantly transformed into his shark-man form until he was in more deeper waters where he then completed the transformation, by turning into small building sized great white. He was able to swim much faster in his fuller transformed state then he could in the half changed one, but that didn't mean he was slow when he was in that hybrid state, he was easily able to out swim a speeding boat with a motor. And as a great white? He left that boat far behind him.
Coming up to a rocky cliff Logan transformed once again into his hybrid form and he started to climbing up the rocks, their sharp edges unable to even leave a mark on his skin, as he continued to climb up dark cloaked figures started converging on him, flying slow but suddenly picking up speed when they went for a pass at Logan.
Logan didn't seem very worried about the Dementors though, reaching out he grabbed the neck of a Dementor that swooped in trying to suck out his soul and at the same time, the tattoo on his stomach was protecting him from the soul attack with it's special ability that Logan had woven in the tattoo, the ability to heal damage to his soul and defend from soul attacks with the Patronus inside the tattoo.
The very same Patronus that had just left the tattoo on Logan's stomach and killed the Dementor that was struggling in Logan's webbed hand, Logan grabbed the cloak and put it into his pocket that had expansion charms placed on it.
The same thing happened time and time again as Logan climbed, the Dementor's seemed unable to learn their lesson as Logan put cloak after cloak into his pocket, looking around Logan noticed that there wasn't many Dementors left.
Dementors formed in places with so much pain and suffer in the air that it can materialise it's self, Azkaban was perfect example of such a place, where the prisoners are treated even worse then dirt, not even meeting basic human rights.
Logan had used a lot of Dementor dust recently with the white dragon and the unicorn and so he was worried about being able the restock when he needed too, "It seems that I'll have to get rid of the rest of Voldemort's slaves in another way." Logan gained a frown that made his shark like face seem even meaner, after that he sped up so that he could reach the top of the prison as soon as possible.
Now at the top Logan spread out his magic around him and let it effect space around him, and he made the wind and rain go around him so that he could safely turn back to his human form, he didn't want to be blown off the top just to climb back up again after all.
"Dobby." Logan called an a half second later a small house elf appeared, with big floppy ears, wearing a butler suit that also had a pin on the collar of a shark tooth to show that he was one of Logan's personal house elf's, Logan could still clearly picture the look of excitement that Dobby showed when he gave him the pin and told him what it meant.
"Yes, Master White? What you be needing from Dobby?" Dobby asked excitedly, happy that Logan was asking him to do a job so that he could work, and he loved it when Master White gave him work!
"Land the house at site A, and prepare the basement for me to apparate something 'very' large into it. And make the basement as large as possible, the same size as the house elf living area should be big enough." Logan told Dobby, sending him away so that he could get the house ready for what he planned.
After Dobby popped back to tell him that things were ready Logan transformed back to his Shark-man form and took back in the magic that he was using to protect himself from the weather.
He then started building up all the magic he had stored up inside his core, pushing his magic to raise in power and quality, once he felt that he had grabbed enough from inside himself he started coating the tower be nether him as quickly as his magic could travel, just using so much magic at one time was a lot of strain on his body and so he needed to be as quick as possible.
Once he felt that his magic was coating the entirety of Azkaban he held it for a second so that he was sure that he wouldn't suddenly lose control and that his magic was steady enough for what he was going to do next.
One second the tower was there and the next there was a empty space that the ocean water rushed in to fill the gap.
The Dementor's flew around where the tower used to be, like they were confused about something but it was hard to tell when their faces were covered with a hood and anyone that wasn't Logan was too scared to get close enough to find out what was underneath, in fear of getting their soul sucked out.
Something even stranger started happening to the Dementors, a small figure in completely black clothing that cover their entire body and with a white mask on their faces, small like a Goblin but thinner, they would land on the back of a Dementor and before they could even react and try and suck their soul out they would disappear with the strangest sound, like popped bubble wrap.
And within just a couple short minutes the Dementors had all disappeared as well and all that was left in place of the dark prison was a stormy sea that looked to becoming calmer, like the sea's were glad that all the Dementors were finally gone.
...
"Good job everyone! Keep them coming!" Logan yelled out encouragement to the Shadow Elf's, a group of house elf's that Logan was trying to train to become his little assassin's, he was having some luck with it but they still needed more training and a dedicated instructor, Logan simply wasn't that person.
After a house elf brought in a Dementor and put it with the prison tower that Logan had stolen, still filled with prisoners, they would pop over to Logan's side where they would sit under the blue mists that Logan's Patronus let off as it stood beside him, the blue mists fixing any damage their soul's suffered in the short time they were in contact with the Dementor.
"Bat." Logan called and just like that a shadow elf, popped to his side on their knee, silent and ready for an order, looking down at Bat Logan saw the white mask that he gave him once he graduated from the Shadow Elf Training Academy, the mask had some blue markings that reminded him of a bat and it looked quite ordinary but Logan had put in so many charms and spells that it could be compared to a low level Hogwart's founders artefact so it was far from it.
"Start gathering all the guards and all prisoner files, obliviate the guards if a mental scan doesn't show any crimes that they might have committed, if they have, throw them in a cell." Logan told Bat, sending him away right after.
Logan had gone to Azkaban to end all the rest of Voldemort's followers but in the moment he realised that he would have lost his Dementor factory, so he decided to take it instead and using it as his own prison in his basement.
He had moved the tower into an enlarged space in his basement, so that there was enough room for the tower and for the Dementors to fly around, he had even made it so that it was surrounded by a small ocean that he was having the elf's moving all the water magical creatures too, he even had the squid from the Hogwarts lake here, that actually turned out to be a kraken, not a squid, who knew?