I can tell you an excellent strategy to get beat this level.  When you start, run straight towards the mirigore, jump and do a knockout jump kick (both attacks together).  It will knock the guy off the mirigore.  (every once in a while the mirigore will stop you in your tracks with a tornado attack.  Just replay again).  Once you knock him off, you will likely be on top of or very close by the mirigore.  Quickly mount the beast.  Turn around go into a rage (strong attack).  Now, just go wild and kill kill kill.  Every kill gives you more and more titan percent too.  When your rage runs out, engage it again until all the enemies in the first part are gone.  Now, go and kill the lone conjurer quickly with a nice combo attack.  Your worst enemies in this first part are gonna be those damned red gnomes that spawn when the 3 demons die  Ways of avoiding them while on the slow mirigore is to be in the act of killing a demon dog or engaging rage mode (both cut scenes) when they dive at you to explode.  Once all enemies in the first section are dead, go around and get the health at the back of the bridge where you started, and right before the doorway to the next part, then collect the two tribute chests.  Take the mana if you want, but its useless really. 

Now, onto the second part and probably the hardest.......