"The" is used because "Almighty (സർവ്വശക്തൻ)" is a specific and unique entity, often used as a proper noun to refer to God or a higher power.
Phrases like 'Almighty God', 'Almighty Allah', or simply 'Almighty' (when used as a noun) refer to the Divine in the singular, and refer to a specific conception of the Divine, so they go with the definite article ('the').
