To reach high levels with ceric: 
1. go to the slime level 
2. go into the area inside the bottom left corner 
   which is surounded by trees
3. block entrance with magic shield
4. turn speed up to full
repeat 3. until the number of slimes reaches 135
5. then use the mystic mace to kill them

NOTE: you need intelligence to be above 50
NOTE: only have one cleric in your army at that 
      time (nothing else)
Note: if health runs low go back into the original 
      area till your health is recovered
NOTE: they only multi increase there numbers 
      once so make use of it.