I'll try not to be picky, I do have my favorable Sans VAs in the fandom but I'm willing to listen to a variety of auditions. In general, a voice that's low and perhaps a bit gravelly. What would be voiced is all of the dialogue of the fight. Every line. I'm going to run the fight as though Chara wins on their first try, so everything that kind of playthrough would entail. That means pre-battle, during, and ending/death dialogue.