Appearing before Prince Yriel during The Battle for Iyanden as he took up the Spear of Twilight, Veilwalker had vanished and did not appear again before Yriel until he had attempted to return the Spear and die in the process. Veilwalker told Yriel his job was not yet done and showed him a vision of the future, of Eldar Gods reborn and Daemons loose upon the Stars. After seeing what lay ahead Yriel took up the spear once more, and the illusion of Veilwalker faded away and beckoned Yriel after her into the shadows of the shrine.
Another act of that person was the trick with the Tau colonisation of a planet Maudlin III. In disguise, the Shadowseer came before the Water caste as the ambassador of an alien civilisation. With silvertongue words and a description of the future peace, she told them of her planet, Maudlin III. The Tau were tricked into landing there, expecting a new xenos civilisation, though what they found was only world with relatively poor life. Next, the Veilwalker had lured a tendril of Hive Fleet Kraken from its course, and goaded them to Mauldin III, which now was relatively teamed with living beings. So were destroyed a thousands of Tau, but was saved from the Tyranids menace the important webway portal.
During the Thirteenth Black Crusade, Sylandri Veilwalker appeared before the Magos Belisarius Cawl, directing him to a world devastated during the 4th Black Crusade to recover an ancient artifact. It later was revealed that Veilwalker was working with Eldrad Ulthran, and helped guide the surviving Imperial defenders of Cadia into the Webway. She later reappeared alongside Cypher and his Fallen Angels to free the resurrected Roboute Guilliman from Chaos forces during the Terran Crusade. Veilwalker was vital in the battle against Magnus that followed, sealing the Webway Portal on Luna after Guilliman forced the Daemon Prince back. Afterwards, Veilwalker and her Harlequins vanished.
- 1: Iyanden: A Codex: Eldar Supplement (E-Book), pg. 48
- 2: Warhammer 40,000 7th Edition Rulebook (E-Book) - Time of Ending
- 3: Harlequins Painting Guide – Warriors of the Laughing God, pg. 54
- 4: Gathering Storm: Fall of Cadia - Chapter 3
- 5: Gathering Storm: Rise of the Primarch - Part 3