[He wanted, even needed, to believe his brother's assurances, but there was so much doubt. That was one of Sidious' powers, to sow doubt and discord in a logical manner, and he could still hear some of those whispers if he allowed his thoughts to focus on what the experience had been like. It shouldn't affect him like this; he was a warrior, a Nightbrother who had survived childhood, trials, hunts and even becoming a monster from Nightsister magic.

His arms tightened to a nearly bone-crushing degree around Maul, and he butted his head towards the hand against his skin.]

I know you will, brother. You can't... don't ever let his spirit infest you either. I know you're stronger than I am, but he will do everything he can to destroy you from the inside.

[Perhaps what he feared more was his brother falling victim. His brother had a stronger character, and with these new skills, he believe Maul would fight Sidious off. Still, the fear made it easy to shift to anger in defense of his elder brother, if only mentally right now. Hence why he remained clingy.]