Eddie the Cranky Gamer
It is your whole turn. You don't get to do anything else.
Edit: Hey lets quote some rules
The player can make no conquests during the turn his race
goes into decline; his turn ends immediately after scoring! He
gains 1 Victory coin for each Region his newly In Decline tokens
occupy, but unless stated otherwise, he scores no Victory coins
from his now In Decline Race banner power or discarded Special
On his next turn, the player will select a new Race and Special
Power combo from among those now available to him.