While he was relaxing in the Manor, waiting for the others to get trained up enough that they could travel, and for the Lamia to hatch, Cain had prepared just the right spell for this situation. A modified version of [Warming Hug] at the Ancient Grade called [Comforting Touch]. With a single touch, while the spell was active, the recipient would feel welcome, wanted, and cared for. the effect got stronger if the emotions were already present, and with prolonged contact.
As the Bunnies gathered around to greet the group, Cain activated the spell and reached out to gently pat heads wherever they came in reach. It was clearly working and the Bunnies looked overjoyed to see him, with many even stopping to give him a hug before going to visit their High Priestess, Jessica.