As much as attacking my personal code would annoy me, I've dealt with it on a regular basis (being a vegetarian)... so be aware that doesn't always work.
Exposing the weaknesses of the INFJ character. The introversion, the spaceyness, etc.
Really, the most effective thing would be showing cruelty to those weaker to you. Obviously doing that would be wrong, maybe lying about doing it? Granted, if this INFJ could cruelly hurt someone, it may not work on them. This is either an unhealthy INFJ or they were pushed for a long, long time.