Hitler decided to use ‘Swastika’ as the Nazi symbol after reading about it in a book
This is a “Swastika”, which originated thousands of years ago in India as a sacred symbol of spiritual principles in Hinduism and later accepted by Buddhism and Jainism. It is also a symbol of happiness, prosperity & good luck.
But Adolf Hitler read about it in a book and changed it’s meaning forever, making it a symbol of hatred and racism.

The cover of one of Helena Blevestky’s books with the Swastik sign (under the crown in this picture)
This was a book written by Madame Helena Blevitski, a Russian occultist and she founded of the Theosophical Society in 1875. She moved to India in 1880 and founded the “Arya Samaj”.
In her esoteric work, especially “The Secret Doctrine”, published in 1888, Blavatsky emphasised the concept of races as paramount in the development of human history. According to Blavatsky, there are seven root races of mankind, with each root race containing seven sub-races. The present root race is the fifth, the Aryans, who evolved from the fifth sub-race of the Atlanteans.
According to Blavatsky, "The Aryan Race was born and developed in the far North, though after the sinking of the Continent of Atlantis its tribes emigrated further south into Asia, following a migratory pattern that went south and west from Asia, ultimately created the great Hindu, Persian, Greco-Roman, and later European cultures.
Blavatsky considered the swastika as a powerful occult symbol of the Aryans and used it in the seal of the Theosophical Society. Hitler read her books & was inspired by her writing about races and how (so called) superior races lwere spiritually enlightened and intelligent and “better” than others.
In Mein Kampf, Hitler viewed the swastika as symbolizing "The mission of the struggle for the victory of the Aryan man, and ... the victory of the idea of creative work, which as such always has been and always will be anfi-Semific.”
He later went on to adopt it as the symbol of Nazism, which supported the theory of dominance of a superior race over the others.
And this is what he made it look like.
A symbol of hatred.
PS: Everyone needs to understand the difference between the two:
If you ever travel to India, or go to a Hindu family’s home anywhere in the world, you may find the Swastik in the left. It is auspicious to Hindus and they believe it will bring them good luck and prosperity.
It has nothing to do with the Nazi Swatika in the right, which was conceptualised by idiots claiming they were superior to others.
However, you may find the Nazi swastika displayed proudly by people in the west these days who still believe in ideologies they don’t have an idea about.
You can ignore them and wish they get some sanity in life someday :)
Image source: Pinimg