My name in Kanji (Japanese)?

Maybe the pronunciation of your name should be translated into kanji, not the meaning of your name.

For example, if your name is Alessia, the kanji will be 吾礼志亜 (read as Areshia).

If you want to translate the meaning of your name into kanji, I'd write:

防人 read as Sakimori, which is the worriors who defended Japan against foreign powers in ancient times.

防=prevent, defend

人=person, people

or

守人　Morito (this is a Japanese first name for men)

守=protect

人=person, people

or

衛士 Eiji (this is also a Japanese first name for men)

衛=defend

士=samurai

Hope you like them.

How about ウルトラマン(Ultraman)?

Although not Kanji but Katakana, but his duty is quite suitable for your name:)