[The Unlucky one]

Chansey is very similar to Genesect in OU. Chansey and Gene both do have a couple of counters but it makes a 2 pokemon core wall/sweep a majority of the metagame. For Genesect it was Gene+Duggy while for Chansey it is Chansey+Cofagrigus. Chansey lives a lot of fighting type moves as well and can retaliate with counter. Counter Chansey is another force in OU that is incredibly hard do deal with especially with Lunar Dance Cresselia backing it up.