Barbarian Berserker can setup huge damage for Wizard, Sorcerer, Druid (Anyone with AOE Lighting or Frost Damage spells). Throw water bottle via enraged throw in your bonus action and as long the Wizard/Sorcerer/Druid have some sort of chromatic orb/call lighting etc to follow up with using frost/electric attack.
Those classes can their bonus action to use haste potion and cast call lighting twice for 3 turns. It pretty much kills most enemies if not all. Auntie Ethel dies fast once wet, and you have a hasted wizard, druid, sorcerer ready with some high damage for 3 turns. Never need to worry about enemies. Keep those water bottles for your barbarian.
