Water cant beat amaterasu plan and simple it was raining and amaterasu was still burning in the itachi and sasuke fight it burns until its target is destroyed no matter what unless its uer puts it out as shown by both itachi and sasuke.A water wind comb will most lkely not work either.Amaterasu can only be used so many time as it costs so much chakra as we see you can out run it.Itachi used tsukoyomi once amaterasu twice and susanoo and once and then he died.He also used to grand fire ball jutsus besides the first couple of genjutsus.That speaks about how much those jutsus take out of you.Susanoo is most likey a one shot deal but I`m sure not all susanoos have the sword and shield only itachi since they said Orochimaru was looking for that sword but itachi had it all this time so only itachi should be allows to use that sword.