Stuff like "Actor 1 used Ice Volley!" or "Actor 3 is suffering from poison." I think you can change it in the engine's code, but I'm not 100% sure. So if you don't mind using plugins, Yanfly's Battle Core let's you change without doing all that digging.
That is the battle log, and you would need to do a script mod to change it.
I've moved this thread to JS/Plugin Support. Please be sure to post your threads in the correct forum next time. Thank you.
Your profile says you primarily use VX Ace, but you posted this question in the MV forum. Which one are you using? The answer will be very different. If you ARE using Ace, I'll need to move the thread again.
Apparently MZ lets you preview move routes in the move route editor without having to start up test game. That could save a lot of time during development compared to MV, especially for a long game that uses a lot of event movement for cutscenes.
Working on a Premium version of my minimap plugin that will have advanced functionalities such as drawing a Terrain map based completely on the users tilesets, whatever they may be, and drawing minimap radar icons automatically based on texture of the event the note is applied to.