devastating vs annihilative

devastating and annihilative both are adjectives.

Word	Noun	Adjective	Verb	Adverb
devastating	No	Yes	No	No
annihilative	No	Yes	No	No

As adjectives, devastating and annihilative are synonyms defined as:

devastating and annihilative: wreaking or capable of wreaking complete destruction

Other synonyms of devastating include annihilating, withering.

devastating (adjective)	annihilative (adjective)
physically or spiritually devastating; often used in combination	wreaking or capable of wreaking complete destruction
making light of
wreaking or capable of wreaking complete destruction