I imagine Rayquaza's wish would be to always know what Groudon and Kyogre are up to, even when it's in deep slumber, hence the 2 new heads feeding the main head(the toxic chained one) information of Groudon and Kyogre. However, these 2 heads tend to bicker, causing the main to stop the ruccus..
The other head with the mouth open, is Groudon's information. The one closed, however is Kyogre's information..
I tried to make the pattern on Rayquaza look like the Toxic Chain, if you're wondering why it's bigger than normal.
