The fusion of Ceremonial and Executive Powers is a distinctive feature of the Presidential system of government.
Presidential system of government is the one in which the head of State of a country is also the head of government of the same country. It is a system in which all executive powers are vested in one person with the title of the Executive President.
As head of State, he has the power to sign a bill into law. In case of anomalies, he can refuse to sign a bill until the anomalies are corrected by the two House-House of Representatives and the House of Senate.
Coming to Ceremonial Functions, he represents the country at some events such as taking salute at parade grounds on independence day celebrations.