Valid and Devastating

adjective

• Well grounded in logic or truth or having legal force.
  • usage: "a valid inference"; "a valid argument"; "a valid contract"
• Still legally acceptable.
  • usage: "the license is still valid"

• (a.) Having sufficient strength or force; founded in truth; capable of being justified, defended or supported; not weak or defective; sound; good; efficacious; as, a valid argument; a valid objection.
• (a.) Having legal strength or force; executed with the proper formalities; incapable of being rightfully overthrown or set aside; as, a valid deed; a valid covenant; a valid instrument of any kind; a valid claim or title; a valid marriage.
• (a.) Strong; powerful; efficient.

Legally binding; authorized.

verb

• Cause extensive destruction or ruin utterly.
  • usage: "The enemy lay waste to the countryside after the invasion"
  • synonyms: lay waste to, waste, devastate, desolate, ravage, scourge
• Overwhelm or overpower.
  • usage: "He was devastated by his grief when his son died"
  • synonyms: devastate

adjective

• Making light of."afire with annihilating invective"; "a devastating portrait of human folly"; "to compliments inflated I've a withering reply- W. S. Gilbert
  • synonyms: annihilating, withering
• Wreaking or capable of wreaking complete destruction.
  • usage: "possessing annihilative power"; "a devastating hurricane"; "the guns opened a withering fire"
  • synonyms: annihilative, annihilating, withering
• Physically or spiritually devastating; often used in combination.
  • usage: "a crushing blow"; "a crushing rejection"; "bone-crushing"
  • synonyms: crushing