守護者, while it looks like a RPG class to me, is maybe the closest thing (守護 is also used when translating western concepts such as "guardian angel" or "patron saint"). If you really must do this, try to find a tattoo artist who knows the language or get someone to do a proper calligraphic design for you, rather than using some ugly computer font.
I have looked at Japanese tattoo sites out of curiosity before and even Japanese people who are into tattoos don't really do "kanji tattoos" that much. They do use a lot of random Sanskrit and, of course, English. Everything is exotic to somebody, somewhere.
In fact, if you google 漢字 and 刺青 you will probably first get a bunch of articles about foreigners and kanji tattoos with accompanying rather caustic commentary.