The Deity of Sri Sudarshana Narasimha has Lord Narasimha on one side and Sri Sudarshana on the other.
Lord Narasimha is the half-lion half-man incarnation of the Supreme Lord who appeared to protect His devotee Prahlada from his demoniac father Hiranyakashipu.
In the Brahma Samhita it is stated that Ganesha always holds the lotus feet of Lord Narasimha and thus he obtains the power to destroy all the obstacles on the path of progress in the three worlds. Devotees pray to Lord Narasimha for protection from evil influences and for removing all obstacles on their spiritual path.
The Sudarshana chakra is eternally carried by the Supreme Lord (Vishnu or Krishna) as His personal weapon. The Lord uses this weapon for the protection of His devotees and this disc is extremely fearful to the non-devotees. It is the most powerful weapon, greater than the Brahmastra or similar other disastrous weapons. Lord Sri Krishna used the Sudarshana chakra to kill Sisupala, a rival of the Lord. He also killed Salva by this weapon, and sometimes He wanted His friend Arjuna to use it to kill his enemies.
(Mahabharata, Virata-parva 56.3).