Moku flies away with a platinum tier danger arachnid bee chasing behind him. If Moku slows down even a little then surely he will have to face the platinum tier danger arachnid bee. Right now he doesn't want to fight platinum tier danger arachnid bees because he has a bigger risk with silver and golden tier danger arachnid bees helping it and also because this doesn't match Mige's plan.
Mige wanted to slowly reduce the number of Quadruple Arachnids and bring this battle to Bitter Maja where the decisive battle would take place. This plan was intended to thin the enemy's supply and also to hide their presence from the 30,000 mage troop.