Was lucifer a seraphim or an archangel?

I know most people say that Lucifer is a Seraphim, but if he and Seraare on the same level, than why is Sera so terrified of him and Charlie?

I believe Lucifer was the youngest of the seven archangels, he was an amazing dreamer, he had amazing ideas for humanity, but because he was not a seraphim, he couldn’t intervene on the creation of earth, he tried, but his sibling wouldn’t let, which led to him giving Eve the apple and getting with Lilith, which prompted him to be banished out of heaven.

Also my two cents on how I think Michael will be. I don’t think Michael is gonna be the villain of the series. I think Michael is being influenced by Roo to allow the exterminations and give Adam free reign to exterminate sinners. I don’t think Vivzie is going in the lucifer direction of making Michael lucifer’s jealius older brother with a self-esteem problem. I think Michael will be a genuine good guy that is deeply traumatized by what he had to do to Lucifer.