Black Mahakala Thangka
This 6 Armed Mahakala Thangka, is a common deity to Buddhism, Hinduism, and Sikhism. In Buddhism, Mahakala acts as a protector or guardian god known as a Dharmapala. Dharmapala is an angry god or fierce deities whose job is to defend or protect the law. Angriness is meant to represent their ability to defend and protect Buddhist followers from threats and enemies.
Basically there are two kinds, one is a worldly protector whereas the other is a wisdom protector. Only wisdom protector is enlightened beings.
Now, according to Hinduism, Mahakala is a Shiva manifestation and is the companion of Hindu Goddess Mahakali, and appears most prominently in Shaktism’s Kalikula sect. Lastly, Mahakala is referred to as Kal, the ruler of Maya (Anything that pulls us away from God) in Sikhism.