As Eric was told about this sudden change of quest, he had no choice but to agree even though past insecurities are kicking in. Think about it, Eric is an all powerful Electus who has the capability to wield all 8 of the base powers yet he wasn't strong enough to even scratch the nicknamed Man Beast.
Sure he later found out that the reason behind it is indeed large, theft of power and murder as a motivator. That helped tame his insecurities just a little bit when it comes to dealing with such a disaster of an enemy, but now he has to face them again.
Even though both him and Mogranius qualify as Experts(Level 4) In Fire Controlling, they still can't out match a man who is even more powerful than a fully trained Electus! What good would it do to Ignis considering that they are practically flying to their death.
