Here are examples of the word/phrase "fortified" used in a sentence and paraphrased in a sentence...
The castle has been completely fortified on all sides.
The castle has been completely reinforced on all sides.
By adding these new cards I think I have fortified the defense of my deck.
By adding these new cards I think I have strengthened the defense of my deck.
Using performance enhancing drugs fortified his overall performance but he was eventually exposed and banned.
Using performance enhancing drugs invigorated his overall performance but he was eventually exposed and banned.
Other Examples...