The cup, the sword and the mirror discussion

this is where definitions are

Shadowhunter
in short: deamon hunter
Several thousand years ago, demons found a way to exploit the thin veil between our world and theirs. In an attempt to save humanity, a warlock called forth an angel, Raziel of the Nephilim, who spilled his blood and the blood of humans onto the Mortal
Cup, from which fierce warriors drank. These warriors became the world's original Shadowhuters. The Shadowhuters are bound to protect the mortal world from demons and Downworlders.

RUNE
Ancient marking thatt the Shadowhunters pianfully carve into their skin, which imbues the wearer of the mark with extraordinary powers. The specific power, such as speed, agility, fortitude, or clairvoyance. depends on the type of rune carved. Placement on the body alters the effectiveness of the symbol; the closer to the heart, the more powerful it becomes. Without runes, a Shadowhunter is extremely vulnerable.