In the battle

"Duel skill name"  (actor1's name): MPcost (actor2's name): MPcost

If the Duel skill name and the actor's name are too long, it may not look nice.

Can I edit away the details of  this part?-->  (actor1's name): MPcost (actor2's name): MPcost

You can either use icons or turn on the "Cycle Actors" option. (Or even both at the same time!)

There are multiple ways you can handle icons. The simplest for a non-coder is to use this plugin (it's free!): https://heroicjay.itch.io/actor-icons NOTE: I never updated this plugin for MZ, but setting an icon through <icon:##> should still work even there.

"Cycle Actors" is an option in the plugin settings. It makes it so that only one actor's details appear at a time, and the displayed actor will cycle every second (by default; there's also an option to make it shorter or longer.)