Okay so here is what I don't like about Mystic Water: Icy Wind is extremely weak. Secret Sword actually does a bit more to Ferro (around 71%, which is normally a living range vs. Scarf) and Icy Wind does like 47% to Among with EB (after SR and sand its a 2HKO). You miss those if you run Mystic Water; however, it does seem like a good idea as Hydro Pump is boosted tremendously.
I really disagree with it not being able to pull off a worthy bluff. A lot of things will think your locked into Icy wind and switch into ice resists (see Scizor), which you can then Hydro Pump and take it down. Landorus-I also tries to set up RP on those SS locked Keldeo. How much have you used it? It's not the fact that its going to be hitting something SE all the time more than you can simply KO something that is trying to resist its locked coverage move (SD Scizor, RP Landorus, Rotom-W comming in on Pump to get KO'ed by SS, Forretress coming in on Icy Wind vs. your DeoD team, hitting Jirachi with Pump when it tries to CM on your Icy Wind, etc.)
I'll take out the part of bluffing specs in rain. I'll also take out HP Ghost, which is quite a bad mention on my part since its inferior to HP Electric.
Life Orb takes all the bluff away which is why I feel it needs to stay as AC, as thi sets main job is to bluff. Mystic Water is certainly a good slash to EB, so I will do that
Log of Keldeo pwning Sun with RD. (Although he turned out to have Sunny Day Venu, but you'll see that setting up that SD was vital for my success). Here!
This one is even better: here
! This is also a great example of Keldeo's bluff, see when Dragonite switches into Keldeo to tank Pump but gets blasted by Icy Wind (@jc104)