bucket on him and you have got yourself a water bender. he doesn't do much but trade things with you. you need waterbending-experience to trade with
him. to get waterbending-experience, you must throw a nether star into a water source block and it will spew out everywhere! once you have gotten the
clay, I mean "waterbending-experience" trade with the villager and you are now officially, a waterbender. to use the waterbending magic, simply drop the
item on the ground and watch the magic. Enjoy!