Here are examples of the word/phrase "susceptible" used in a sentence and paraphrased in a sentence...
The vampires may be hard to deal with in a dark environment, but they are susceptible under sunlight.
The vampires may be hard to deal with in a dark environment, but they are vulnerable under sunlight.
You are susceptible to that type of attack. Let him go instead.
You are vulnerable to that type of attack. Let him go instead.
If you don't wear your armor you will be susceptible.
If you don't wear your armor you will be vulnerable.
Other Examples...