Basic Action Super Heroes!

A question came up about the application of XP.

If a player wants to spend XP to add a power to an existing multipower, how much does it cost?

6 or 12? Since normally it would cost 1 or 2 points during character creation... or is it more?

Thanks

It would be 6 to add a power of the same category, 12 to add a power of a different category.

Thanks for the info sire