CHALLENGE 1: green goblins are easy, red goblins absorb explode, shadow goblins resist all except dragons breath
CHALLENGE 2: its very easy once the big bomb exploded
CHALLENGE 3: use fast meelee units, once they come close baal they become invulnerable to baal's sword slash. You can also use invulnerability. the fire titan is a very great help. and once you defeated baal its just a piece of cake!
CHALLENGE 1: green goblins are easy, red goblins absorb explode, shadow goblins resist all except dragons breath
CHALLENGE 2: its very easy once the big bomb exploded
CHALLENGE 3: use fast meelee units, once they come close baal they become invulnerable to baal's sword slash. You can also use invulnerability.