The two on one "universal grip break" is probably my current favorite technique to use in most situations, but it works incredibly well from the RNC defense. Start with a Kimura grip for this one. You are attacking your partner's right arm, and your right hand is grabbing their wrist, while your left arm is laced through their arm. Keeping your left arm in place, thread your right arm underneath your left arm, and then put your right hand "in your pocket" (sometimes making a fist here helps a lot). The general concept here is that you are doubling up the thickness of your forearm, making it incredibly difficult for your partner to keep their arm bent. This is essentially what amounts to a "soft" biceps slicer (soft because all your partner has to do is let go and give up the armbar in order to alleviate the pressure), so use some caution in figuring out how the technique works for you.