The most common tutorial I’m asked for is for a "Blue Mage" skill. For those that don’t know, it’s a job class from the Final Fantasy series, where characters can learn enemy skills. Blue Mages were introduced in Final Fantasy V, which I absolutely love as much as I love the Blue Mage skill itself. I saw Momonja’s tutorial from RPG2K Net (under redevelopment at the time of writing) on Blue Magic and decided to "tweak" it slightly and improve upon it.
So how do you emulate this job class?
Well, there are actually several methods. Here is one of the methods on how to create a Blue Mage Skill in RM2K3.