The game shows that the halo level is the second act of ordinary difficulty and hell difficulty.

Marines with ordinary difficulty will learn to pray for aura, offensive marines will learn to bless and aim at aura, and defensive marines will learn to resist aura. Gunmen with nightmare difficulty will learn Thorn Aura (combat type), Power Aura (offensive type) and Frozen Aura (defensive type). This design is to increase the strategy and diversity of the game.