Not an angry God for sure.
The term ransom was well known (and well used) in those times. The pagan bandits roaming the hills, as well as Roman political intrigue all used kidnapping and ransoming regularly. I believe that the term was used advisedly and deliberately and it meant the same then in Greek as it does now in English.
Death is used as a personalized concept by Paul when he combines the controversial Isaiah 25:8, with Hosea 13:14, namely "death is swallowed up in victory, o death where is thy victory? Where is thy sting?" (1 Cor 15:54-55).
More specifically, lytron was the price paid for slaves or captives.