I wanted to know since I see a lot of people using class taunts, hitsounds, killsounds, announcers, and win/lose music that only they can hear on their end. Thanks in advance.

Have you guys heard of Unholy Bosses? It's basically Versus Saxton Hale except there's multiple classes and you spawn with items that essentially can change the round, for example the rubber band does 10k damage, there are also superbosses that are way more powerful thatn regular bosses, there also special rounds that consist of you fighting against others as a "Demoneye" or "Devileye". It's quite fun and it kinda explains itself once you play it.