The endgame of s4 started three weeks ago. Last weekend it seemed that humanity has a great chance to defeat Zandagort and the alien fleets. But then one of the defeated players of the previous great war between the three biggest alliances took revenge and destroyed a large part of human military forces. Both his own and that of his enemy.
This resulted in a stalemate between human and alien forces. During the last week both sides lost about 60-70% in the battles. And due to the size and scarcity (96% of planets are already destroyed) of the galaxy war had slowed down dramatically.
So Zandagort the impatient leader of the aliens challenged humans to a duel to speed up the end and fight the last battle of s4 in just a day.
We're waiting for the result of that final battle...
