Lavender's first reaction was to let go of Octavius' hand, actually snatching away as quickly as she could. He wasn't acting like himself, and well, wasn't talking like himself. His mannerisms weren't his either. He wouldn't play a joke on her, not about this stuff. It had to be the demon communicating with her.
Her heart started to race at this realization. She wasn't prepared for this to work so soon. "Um... hello?" She bit her lip. What did you even say to a demon that you just summoned? "I'm... Lavender. Who are you?" She asked trying to remain calm.