I propose Dark as one of CAP 5's types. I wanted to concentrate on types and roles that Sun teams tend to lack, which is why I kind of have a problem with all of the proposals for Grass so far (except I guess Grass/Dragon is cool). Dark immediately helps to deal with some of the most dangerous Dragon-types to pit against sun, namely Latios and Latias. These two also happen to have the property that Ice Beam and Ice Shard aren't as gigantic a deterrent to them as most (possibly all) other Dragon-types. Dark doesn't provide much in the way of resistances, but with only two weaknesses, it's that much easier to tack on multiple different secondary types.
In general, I see the typing as more important for defensive purposes than for offensive purposes. This holds especially true with sun teams in mind, since we're trying to deal largely with Pokemon that have double weaknesses, which can easily be addressed using coverage moves. That said, I don't think that we should try to resist a whole bunch of obvious attacking types because this quickly becomes unfeasible. I want to strive for a typing that is at worst neutral to Water, Electric, Ice, Rock and Dragon. The first three are common attacking moves on Water-types; I have Rock because sun has enough problems with Stealth Rock and not dying to Terrakion would be cool; and it would be nice to be able to switch into at least some Dragon-type attacks. I also think that the typing should overall have a good number of resistances, 5+ maybe. This leads me to propose Electric or Poison alongside Dark.
Last edited by capefeather; Feb 15th, 2013 at 10:25:23 PM.