why do you think terezi was immune to vriska's mind control, but none of the trolls were immune to aranea's, not even higher bloods like gamzee?

Vriska was 13 at the time and Aranea had Aeons to practice her powers and get better at them. Also, Terezi is always a good Vriska Counter in pretty much everything, so when WhatPumpkin releases an Overwatch Clone, you know what to change to when you’re getting wrecked by the enemy Vriska.