Letalis was a prophet, but he was condemned and killed by a king who did not like the future that had been predicted to him. However, because death wasn't his destiny to die, he has come back from the dead to fulfill his destiny and predict the death of others.
Several skills reference the Final Destination movie franchise in which group of people who escape impending death when one individual has a sudden premonition and warns them that they will all die in a terrible mass-casualty accident. After avoiding their foretold deaths, the survivors are killed one by one in bizarre accidents caused by an unseen force creating complicated chains of cause and effect.
Several skills reference the episode Mummy on the Orient Express of the series Doctor Who that follows a mysterious entity killing passengers on a train one at a time:
Foretold Doom - the Foretold, the antagonist of the episode
66 Seconds - the length of time victims see the Foretold before their death