General Antonyms:
* Defend: To protect from attack or harm.
* Support: To provide assistance or encouragement.
* Aid: To help or assist someone in need.
* Protect: To keep safe from harm or danger.
* Shield: To guard or protect from attack.
* Safeguard: To protect from harm or loss.
Specific Antonyms:
* Praise: To express approval or admiration.
* Compliment: To express praise or admiration.
* Commend: To praise formally or officially.
* Encourage: To give support or confidence.
* Comfort: To give solace or support.
Other Related Words:
* Soothe: To calm or make peaceful.
* Relieve: To lessen or remove pain, distress, or hardship.
* Heal: To restore to health or soundness.
The best antonym for "assail" will depend on the specific context of the sentence.