In the level that you need to defeat the Norse Titan, enable the "DIVINE INTERVENTION"
code a few times. This will allow more usages of the God Power Healing Springs. Put 
them near all of your allies bases. Then, take the King Frost Giant as well as about
ten Fire Giants and ten Giants to attack. If you have extra resources, build up an 
army to take out the enemy base (in red). The King will freeze the Titan and your 
Giants will do the attacking. This is a good way to defeat the Titan instead of waiting
for the Nidhog.