Even Commander Isaac didn't want to kill mortals. The best he could do was jump over the mortals and avoid them. He would bypass the mortals and plunge himself into the ranks of the enemies directly.
This move helped him avoid the moral dilemma of choosing to kill mortals or not. But it separated him from his army and made him lose half of the power he could wield on the battlefield.
Commander Isaac was threatening on his own. But without an army to use Buff and Army Breaker divine abilities on, he wasn't nearly as threatening as he could be.
He was a knight after all. He wasn't a warrior or giant and wasn't meant to fight alone.
As if things weren't bad enough, someone was killing lamp bearers at the captain level and taking their bloody heart.
Captains are epic godclads. So this hunt for the bloody heart was costing the lamp bearers epic godclads.