In other words, music. Try to keep the theme.
Here's to the memory of the great Vine Ogre horde that stormed the Ermorian Dark Citadel back in the Second Age of Dominions series. The song starts after very in-character declaration of war.
http://youtube.com/watch?v=yPV63iW6gFM
I call this "The Abba marching song" in honor of the greatest hippies of them all. Never mind, you aren't supposed to understand it yet.
http://youtube.com/watch?v=wTWYbzGGIis
Here's to the memory of the Master Druid of Man, whose empire fell on turn 5 when Vanheim rushed him. Incidentally, Vine Ogres aren't a good counter to a rush. The bard in question was caught rising unrest in the wrong province.
http://youtube.com/watch?v=Q2HSQseVwSQ
A famous hoburg troll-hunting song.
http://youtube.com/watch?v=K9WmxwgW2J0
I hear there's a new event in the next patch. It's very rare, creates the site "Crater", and plays this song during the battle. "It's almost refreshing" indeed.
http://youtube.com/watch?v=c4e0cr5aPvY