Here are examples of the word/phrase "valiant" used in a sentence and paraphrased in a sentence...
A valiant knight is willing to die for their kingdom without a second thought.
A brave knight is willing to die for their kingdom without a second thought.
Captain America is so valiant, you'd think bravery is one of his super powers.
Captain America is so stouthearted, you'd think valiancy is one of his super powers.
A valiant super hero would never back down from anything.
A fearless super hero would never back down from anything.
Other Examples...