Last check in for two weeks. Sorry to have bailed so suddenly - the wedding has been creeping up for months and - pow! - it's here! As for tactics against a large group Rainca will, not unlike the first battle, take ranged attackers and casters first using her barbarian speed to close quickly into melee. If there are two or more groups she'll close with the group nearest Dioran, as he's likely to be a target. She'll use similar intimidation tactics that you've seen to cow the more lily-livered sorts and pick out the toughs. If she drops to half HP she'll Rage and tear anyone (barring allies) to shreds, though they're best warned not to approach when she's ridden by the Blood Father.
It's too bad she's not leveling to 3rd... Die Hard! Best. Barbarian. Feat. Ever. Take care and have fun.