This tutorial will tell you how to make 1 skill but with many different effects which is rather pointless, but in case you want to do it, this is the tutorial for you!
Difficulty: Slightly Easy
Let's just start.
First, make a skill like this, in this case the skill will be called 'Lucky 7'. The Skill Type has to be 'Switch' of you want it to be a lot more easier.
Then make another skills with exact name and description
Their Skill Type has to be whatever skill subset you have.
Let's move to Common Event.
Make a Common Event(duh) like this.
The First Branch is the skill with the Skill Type 'Switch'
And then make a variable with a random number according to your skill's number of effects
The Second to the Last branches are your skill effects
i.e: if varXX is 1 the effect will be this
if varXX is 2 the effect will be that
And delete another effects so that the skills won't overlap.
Then we move to Battle Events just to add this one small event.
That event will make the game change the skill effects on every turn. Neat!
You might want to remove the skill effects after the battle ends so that it won't overlap with the skill with 'Switch' as its skill type in the Skill Menu.
So that's it.