Remnant
Remnant is always capitalized in the books.
A Remnant is what’s left behind when a sacred artist dies. It might need to be at the Iron stage or later when it dies, to form a Remnant.
Remnants are made of madra. Humans, sacred beasts, and sacred trees / plants leave a Remnant behind when they die. However, Dreadbeasts do not leave a Remnant, because in life, their spirit gets mangled up into their flesh.
A Remnant can be powerful, but it has only a fraction of the power it had in life. The Remnant from the Sage of the Endless Sword was quite powerful, but not nearly as strong as it was when corporeal.
A Remnant is not the person it once was. That person is gone. It’s only a faint echo of the Sacred Artist.
Many sacred artists use a remnant to advance from Jade to Lowgold. Remnants are also used in Soulsmithing.