Bellatrix Black was known for her loyalty to everything and everyone she considered was right.
The Sorting Hat saw the loyalty, the hard work and the willingness to do everything it took to serve her cause.
And even though her resourcefulness and her stagnant belief in Blood Supremacy finally earned her her deserved place in Slytherin, she always felt that Hufflepuff needed more...
More credit, more recognition, more respect.
And she was going to do it
DS: JK Rowling's universe, I only edit it, the other characters are mine, if you want to adapt and translate tell me first.