Here are examples of the word/phrase "combatant" used in a sentence and paraphrased in a sentence...
His overall skill, speed and strength makes him a worthy combatant.
His overall skill, speed and strength makes him a worthy fighter.
That combatant may be big and strong but he lacks speed.
That fighter may be colossal and powerful but he lacks speed.
A smart combatant can create a good strategy to win.
An intelligent warrior can come up with a good strategy to win.
Other Examples...