Take a look to this proposal
P - Iron Defense
M1 - Hailstorm
M2 - Aqua Jet --> M2 - Ice Shard
M3 - Surf
M4 - Icicle Spear --> M4 - Aqua Blast
M5 - Aurora Beam
M6 - Tri Attack
M7 - Life Dew
M8 - Whirlpool --> M8 - Razor Shell
M9 - Water Tornado
M10 - Blizzard