Skully, the nickname that April had given to him without his permission, acted using those chains to take hold of Chase. Helping in assisting keep him from going anywhere as what April is about to have done within the next second.
Along with that, those chains aren't completely normal since they are infused with magical powers of their own. Able to drain the energy force of a soul to make sure they are weakened for the reaper to finish off unless they have come to trouble on dealing with the lost soul they are assigned to collect.
Chase started to feel it happening as his body became weaker and the rage flames were losing the fire that had been ignited inside.
"What…. What is going on." Chase says seeing has regained the sense of the mind.
Then those eyes see Skully holding the chains that have bound him to his position. next just out of instinct, he couldn't help to look up into the sky and see April standing on the last skull head holding her.