My current take on it. The echo allows you to see into the past events of others, you also cannot be tempered/drowed/will destroyed by a primal because of it(this call into question bahamut's orbs, as the debuff is described as his spritual will overpowering you). A powerful and dangerous trait that not everyone appreciates. The echo buff can be explained as you working of the experience of memories, but its more likely a game trait, as an alternate universe explanation would be...gruesome...
The blessing allows you to resist supernatural influences, magical abilities such as the ones used by ascians. I think this also explained how Garuda lost her crystal to you after she failed to temper you. In lore As you collect more crystals, your own physical abilities also increase, allowing you to solo certain feats done by a party in game. Unlike the echo, which kicks in or is used conciously, the blessing is always active when a crystal of light is in your possession, and gains in strentgh as more are attained.
The blessing makes us powerful, but not invincible. Our strength can be exhausted much like any other being given enough punishment. In addition, as Middie demonstrates, there are ways around the blessing, and I'm pretty sure the WOD/Derplander will introduce another. He needs an edge to make him more than the average lout.
I have my own reservations about the translation, but its at least not in this subject.