[GoseiWonder]

Wanted:
Houndoominite
Adaptability Skrelp and Corphish
Storm Drain Lileep

Also, who wants to try past-Gen warfare? All we do is pick a Gen from 1-4 (as 5 is very recent), and make some Pokemon from that Gen for battle.
Would you ever use a Piloswine in Gen6 over Mamoswine? Of course not! But if you did a strictly Gen2 battle, Piloswine would be an excellent addition.

What about abilities? Some made certain mons better in later gens! Simple, always go with the worse ability in that case. So you'd use Unaware Piloswine instead of Snow Cloak or Thick Fat Piloswine in a Gen 2 brawl.