According to widespread rumour, Blood Angels are essentially clouds of utility fog in the S1 range, who serve the Queen of Pain.
It is understood that Blood Angels can appear in any form they wish, but are usually assigned "uniforms" based upon rank or duties. However current knowledge is limited by the fact that few have ever seen one at first hand and survived.
Seraiph - Text by M. Alan Kazlev A high transapient in the service of an archailect or AI God. May be an autonomous being, or simply the remote of that god. Some Seraphs have seemingly miraculous powers of control over space-time. The most powerful Seraph-like beings are the almost legendary Black Angels.