SmartTube for TV and ReVanced/uYouPlus for Andriod/IOS devices. SmartTube can be tricky to set up depending on the TV, but the mobile apps are relatively simple to get working.

What’s the point in playing nice with somebody who won’t engage in good faith?

If I’m understanding correctly, I think “ERB” here is referring to “Epic Rap Battles” which would make the “starter” the first one to rap in the relevant video.