I just recently got ninja pig from a lucky drop in mooshu. The permanent version of course. I was already planning on getting a myth amulet for earthquake, but if I pvp at level 50 or so should I add ninja pig to my deck at all? I just want to hear someones opinion on the spell.
No. Use Stormzilla. You will get no gear boost (or very little, I'm assuming you have only Storm boost) and you probably won't have any blades. Ninja Pigs has no utility value like Earthquake, stick to your own school for attacks.
At level 50, that's a tough call. I wouldn't try to double as a Storm-Myth, personally. If you plan to stay at that level and never go any higher, I think you could try it under certain conditions. First, you must ensure that your gear boosts damage to myth hits as well as storm hits. This boost should be over 20% in order to make it worth it. You may as well just be Storm if you cannot do this.
Using non-storm spells can be a fun strategy otherwise. Most of your opponents will recognize that you are storm and will put up storm shields, and then believe they are safe. They might not be able to prepare as well for other hits. That said, a lot of people are aware of the common Storm Prism strategy to go around shields, and so they might shield against myth as well. That would make Ninja Pigs useless in battle unless you also carry Earthquake, Shatter, or Pierce.
I just recently got ninja pig from a lucky drop in mooshu. The permanent version of course. I was already planning on getting a myth amulet for earthquake, but if I pvp at level 50 or so should I add ninja pig to my deck at all? I just want to hear someones opinion on the spell.
No. I don't recommend doing that, you'll loose in pvp a lot. If you have stormzilla, I recommend that.