Temporary party

You can use an event (I'm assuming at the end of a cutscene) if you just use the "Change Party Member" command 4 times or however many people you need removed and put into your party.
Then initiate the battle.
After the battle, you can have yet another cutscene or event that switches your party members back the same way.

Just remember that the box labeled "initialize" should NOT be checked when you add or remove the original party members, or else they'll be reset to their default levels and stats rather than saving their progress as far as levels and experience. I doubt you'd want to be in the middle of the game and suddenly find that your characters are level 1 again

Hope that helped!

No, there isn't. But what you can do is use switches.

Just make sure that when they choose their party... Well, say they choose 4 people from a pool of 8. They decide they want 1, 4, 5, and 6. So when they select it, in addition to saying "add to party" you also turn on switches named "Character 1" and so forth for the others. Then you effectively have the ability to check for party members by checking to see what switch is on.

So then you get the party for the one battle, you use it, blah blah blah.
When you have your event set up to add your old party members back in, don't just say "Add Party Member 1" use a conditional branch to check whether the switch "Character 1" is on. If it is, you add the party member. Then it gets to check switch number 2, and they don't have that character. So it says skips over it and goes through all the others until it gets to the point where you've run through all 8, and have a party of 4.

quote ssbm freak

be sure to use a variable to record how many party members are in.
This way you don't put in more than 4.
Jayden can do the specifics. *whips*

NO WHIPPING Dx

But yes, you're right, I forgot about that.
Have another variable, perhaps called "Party" or "Party #" or whatever. Set that equal to 0.
When choosing the party members, have it add 1 to that variable, and have conditional branches outside of each one checking to make sure that the variable is less than 4. Otherwise, it has to skip the others to make sure you're not putting too many people into your party.