This valorous Blade of the Darkmoon appears in Firelink Shrine after you reach Farron Keep. Speak to her, and then explore Farron Keep to find the Dreamchaser’s Ashes. Deliver those to the Shrine Handmaid, and Sirris will appear again, offering the Darkmoon Loyalty gesture.

At this point, her White Phantom sign appears in Farron Keep and the Cathedral of the Deep.

When you reach Irithyll Valley after you battle Sulyvahn’s Beast on the bridge at the entrance to the town, leave and return to check the front of the bridge. There you can find a summoning sign from Sirris. Enter her world and aid her against the invader Creighton the Wanderer. Successfully defend Sirris and she’ll show up in the shrine again to thank you, and give you a Blessed Mail Breaker. In addition, Creighton now invades you later in Irithyll Valley, and after defeating him for his Dragonslayer’s Axe, Creighton’s Armor set appears in the middle of the bridge at the entrance to the town.

Finally, she has one last summoning event directly in front of the Curse Rotted Greatwood’s room. To trigger it, you must defeat both the Greatwood and Aldrich in Anor Londo. Because slaying the Greatwood causes Hodrick to perish, you may wish to visit him before killing the Greatwood.

Successfully aid her in her battle when she summons you to acquire the Sunset Armor set, and she returns to the Shrine and asks to swear an oath of knighthood to you. In addition, she leaves the Sunset Shield by the grave of her grandfather. To find it, look off the right side of the cliff, just past the doors from Iudex Gundyr’s room.

If you accept her vow, she appears as a White Phantom for Dragonslayer Armour and the Twin Princes battles in Lothric Castle and the Grand Archives. Complete those battles, and you later find her corpse by her grandfather’s grave, along with the Sunless Talisman.

Should you refuse her offer of knighthood however, she is found Hollow and aggressive in the Pit of Hollows.

Fully completing her storyline, or killing her causes the Shrine Handmaid to sell the Sunless Armor set.