Periyar used the Aryan Dravida theory as a weapon to poison the relationships between North and South Indians.
He was inspired by the Jinnah's two nation theory and also has a support of Britishers and was quite influenced by British colonisers. https://twitter.com/sahforums/status/1276699191033634816

But unlike Jinnah he don't have any basis(like religion) to make another separate nation.
So he started brainwashing the locals in TN saying it is North Indians are the person who invaded their land and Vedas, Sanskrit is being imposed on them.

Basically he wants to make a difference by promoting atheism.
He also knew that he cannot get successful until the brahmins who were there religion saviours (priests)
So he started filling the hatred in their minds that brahmins are the responsible for all the atrocities.

He started inciting violence against the brahmins in the name of smashing casteism, brahminical patriarchy.
Due to which the most of the brahmins were forced to leave the state and some left the country and these Iyer brahmins were the first who started living in USA.

Also to push the locals away from the religion he abused the God Rama and asked people to worship Ravana also he beaten the photo of Lord Rama with slippers.
At an event even he broke an idol of Lord Ganesha.
It is also quite evident that Periyar was influenced by xtian missnrs

Today the hate for Hinduism, India and brahmins is prevalent and increasing in South India it is all because of this pervert man who even didn't left her adopted daughter and married her.
Even Periyar has made certain derogatory comments againsts the Tribals in TN.

He was against the Sanskrit, Vedas and Hindu but he was also against the Tamil language and Thamizh culture and insisted to learn English only because he wanted to establish the British rule there.