The Sanglyph, also known as The Blood Sign, is an artefact of ancient power created by Pieter Van Eckhardt. It was made from five metallic parts, depicting symbols. The Sanglyph was split into five pieces, and hidden inside five paintings that depicted evil images by Eckhardt. He did this to keep it safe, since he needed it to revive the Nephilim race.
Once Eckhardt regained all the Obscura Paintings, he assembled the Sanglyph once more, in a final attempt to revive the Sleeper, a Nephilim which had survived. He failed, and the Sanglyph was used by Lara Croft to destroy both Joachim Karel and the Sleeper.
The Sanglyph grants the bearer the power to manipulate energy into the form of purple beams or flames, with high velocity. It can also create energy barriers which allow no physical passage through them. Finally, the Sanglyph can make identical copies of the bearer and use them as weapons.