Uno Block Card

The Uno Block Card ( Officially called the Skip Card ) is card so powerful, it outpowers both the Uno Reverse Card and the "No U" insult. It cannot be reversed or No U'd since it is the manifestation of blocking.
It's only counters are Action Cards from the mythical game Dos.

You beat your friend in a game of monopoly
You: Good game!
Friend: Nah you cheated!
You: No I didn't!
Friend: Yea you did! It's easy to tell.
You: Well it was easy to beat you without cheating!
Friend: Your mom was easy.
You: No you
Friend pulls out an Uno Reverse Card
You pull out an Uno Block Card
Your friend becomes bewildered
Friend: I concede, you didn't cheat.