My best friend is terrible but I'm still friends with them.
Okay, but why are you still friends with someone you think is terrible?
I'm loyal to people who I'm friends with. No matter how bad they are
Having toxic friends can lead to bad things. If your friend is horrible you might want to distance yourself from them. It will make your life easier.
Nah, I'll keep being loyal till the end.
I understand your sense of loyalty, but I'm not sure if being loyal to someone isn't a good person is the right thing. You might want to rethink your relationship.