Water will win.
Deeplurker will kill first Khmer Princess (1st turn), than Hill Giant (2nd turn): at this point he will need at least two turns to kill Regal Periton, five if it misses one attack.
On the other hand, Regal Periton will kill first Albatross (1st turn), than Hardy Stonefish (2nd turn), lastly Icie Pixie (3rd turn) and it will need 3 more turns to kill the Deeplurker.
At the end, if Deeplurker misses only one time or less, Water will win.