The Shadow Lord is far more powerful than it initially seems. Though they all fight together, it’s just too powerful. Soon they’re completely overwhelmed, and they’re about to die one at a time.
Zafir calls out before that can happen, attracting the demigod’s attention. He asks the Shadow Lord to forgive Nightingale, that the attack was against his will, and they would like to ask for the initial offer. He will give up his life so the rest of them can leave.
Nightingale tries to talk him out of making the choice, but he has made up his mind. The Shadow Lord kills him in front of everyone, giving them Justice in exchange.