How to have abilities for 2 turns only

[chartboye]

How can I have a special attack increase Evasion for the next 2 turns in a fight?

 

[Kes]

Make a new state in the database. You might have to increase the maximum number of slots if you have not already done so.

In the Features box top right, click on a new line.
Select the Param tab, and on it click on Ex-Parameter button.
Select EVA and specify how many extra EVA points you want to add.
Click OK
In the central section, click on the arrow on the box next to Auto-removal Timing.
Select Turn End
In the box underneath specify how many turns you want the state to last. You say "a couple", so if you want it to last exactly 2 turns, but 2 in both boxes. If you want it to last a variable amount e.g. 2 or 3 turns, but the minimum number in the left box and the maximum number in the right.
Remember to give the state a name and, if you want, an icon. Complete the messages at the bottom if you want.
Hit OK

If this buff is intended for an ally, then
In your skill in the Effects box, click a new line and select the States tab.
Click Add state and then specify what chance you want that this state will be inflicted.
If you definitely want it to be inflicted, then accept the default 100%. If you want less than that, type whatever rate you do want.
Hit OK

If you want it to be given to the person who is using the skill, then you will need to use the damage formula box.

For the sake of the example, let us say that you new state is state 57. Then what you type is
a.add_state(57); damage formula

That damage formula will be the a.atk *4 - b.def * 2 or whatever you are using.