Hellooo,
The code is functional on my end so I assume the problem is with how it was implemented. I don't understand how the code change you mentioned would affect the code, but let me offer some possible solutions based on what I said before.
Since you say it doesn't show up, and not that it errors, I don't think it's a syntax error. Just to be safe, make sure you have the right amount of spaces and all of your capitalizations match. True and False are capitalized too when you change the variable values! Was the character set to True?
When you changed the variable name to Riot, are you certain that everytime it's mentioned in the script is changed too? CTRL+F to search for character3 it just in case!
Are you using $ metcharacter3 = True in the right spot? (Or however you name the variable, doesn't matter much) To be as clear as possible, this line goes inside the "script.rpy" after the start label to change the variable during the game.
When you updated the character lists, did you update each and every screen? This plugin setup is a bit inefficient, so you have to edit the data on each individual page, including the character list section. If you updated all of the sections, you will have the same code change multiple times. You'll find a new one under each "screen," so you'll make this change for every separate character!
Other than that, I don't have many more ideas what it could be. If these suggestions don't help, then please share with me the parts of the code you've edited and maybe I'll have a better answer! Good luck!