Biologically immortal. The mortality rate is extremely low; most survive for hundreds of years.

Seraphim are Energy Beings, but unlike most others, they do not have a "default" physical form and can change their appearance at will. There are common traits that make them identifiable. Regardless of form, they have large, white-feathered wings that they cannot hide; the size is directly proportional to the Seraph's power. The eyes are a brilliant shade of gold, silver, or blue, and give off an otherworldly glow. This glow is often mirrored in the rest of their body, but unlike their other constant traits, Seraphim can "turn off" the light emanating from their body at any time.

Seraphim do not have a permanent sex, and gender is entirely a matter of personal preference. Some lean one way or another in the forms they assume and the pronouns they prefer, while others choose to ignore it completely. Technically, they are hermaphroditic, with all of them capable of birthing young.

As guardians of The Hereafter, Seraphim possess a number of unique powers. First and foremost, they have complete command over their physical form, usually choosing from the appearances of the races they watch over. To further accommodate the deceased, they can "learn" the spoken tongue of any being – including other Seraphim – through brief physical contact. Those that are selected to guide the souls of the deceased are also granted the ability to peer into the souls and memories of non-Seraphic beings.

Against Shades, Seraphim wield all sorts of physical weapons, but when facing against other threats, they can unleash a wide array of powerful magic. As timeless creatures, they have a deep understanding of Old Magic and how to utilize it to its fullest extent. All Seraphim command Light Magic, Dark Magic, or both. Soul Control magic is fairly common as well, used to maintain order amongst the Ghosts they watch over.

Each Seraph is assigned a post, either on one of the Hereafteran lands or out in the Void Tunnels. To abandon this post without proper authorization is high treason, usually punished with an extensive exile sentence of hundreds of years. The majority of Seraphim are "Peacekeepers," and are charged with watching over the Ghosts and ensuring that everyone remains as content as possible. Others known as "Charons" retrieve the souls of the recently deceased and prepare them for their new life. "Defenders," the second highest rank, spend most of their time in the Void Tunnels, guarding them and the worlds they connect from Shade attack. The most powerful of Seraphim are known as "Thrones." They serve as the leaders and enforce Seraphic law.

Though Seraphim are forbidden from giving sensitive information to most ghosts, Chosen Ones are the exception. Beings chosen by The Creator are given special treatment in death, including the freedom to cross between Hereafteran worlds and speak freely with Thrones.

In order to keep the population under control, only Thrones are allowed to give birth to and raise baby Seraphim, sometimes called "cherubs." Any cherubs found under the care of a lower-ranking Seraph are immediately culled.