Sylandri Veilwalker

Sylandri as she appears in TTS (There's no canon art of her)

Sylandri Veilwalker is an Eldar Harlequin Shadowseer who is part of the Masque of the Veiled Path. To say that she's been involved in a LOT of things over the millennia is a bit of an understatement.

Mask within Masques

"Sylandri Veilwalker" is not the name of a singular individual. Rather, it is a role that many different Shadowseers have taken up throughout the millennia, usually to pursue an agenda only known to the Troupe Masters of the Veiled Path. What IS known is that, whatever that agenda is, it doesn't make the Masque a lot of friends.

Sylandri and her Masque have since then been shown to be aligned with the Ynnari, which means that, at the bare minimum, they think that the Seventh Path has merit.

Known "Interventions"

• The Soulspear: Convinces Corsair Prince Yriel to take up the Soul Spear in a last-ditch effort to defeat the Swarmlord leading the ground attack on Craftworld Iyanden. Yriel defeats the uber-Hive Tyrant, saving his Craftworld, but his soul is now tied to the cursed weapon.

• Ancient Secrets Uncovered: Makes Archmagos Belisarius Cawl continue digging at Eriad VI despite the latter wanting to abandon it due to Ork raiders. This leads to the discovery of the destroyed Pylon fields there, which then forces the Archmagos to hurry to Cadia and help in the defense there.

• The Spectral Guide: Guides the Terran Crusade through most of the dangers of the Maelstrom. It doesn't quite work in the Imperium's favor however, as they get ganked by the Red Corsairs and get most of their ships stolen. This leads to...

• A Fallen Intervention: Aids the mysterious Cypher and his Fallen cronies in first freeing Roboute Guilliman and the rest of the Terran Crusade from their imprisonment, and helps them excape to the surface of Luna via Webway gate.

• Against the Red Cyclops: Assists the Avenging Son defeat his traitor brother Magnus by forcing the daemon prince back through the Luna Webway portal, then detonating it.

Other possible appearances

• Red Portents: Might be the Spiritseer that reveals to Mephiston the threat of Ka'Bandha during the Devastation of Baal. As the Blood Angels and its successors can ill afford diverting their attention (and forces) from the Tyranids, Mephiston and the combined Librariums of the Successors there pre-emptively confront the Bloodthirster before its forces manifest on the embattled world. At least some people are taking this genuine alliance thing seriously! And look how awesome the results are.

Famous Ynnari
The Big Three:	Yvraine - Visarch - Yncarne
Ex-Craftworld:	Eldrad Ulthran - Jain Zar - Prince Yriel - Iyanna Arienal
Ex-Dark Eldar:	Lelith Hesperax
Harlequins:	Sylandri Veilwalker