Dreamchaser's Ashes is an Ash in Dark Souls 3.
- Unlocks at the Shrine Handmaid :
- Behind an illusory wall near the Watchdogs of Farron covenant location
- Video location (fextralife video starting at 1h 31m 26s)
- Turning this in will evoke new dialogue from Sirris if she is still your ally. This is the fastest way to gain her gesture.
It could be that these are the ashes of Sirris's Grandfather as he wears tattered Farron Armor that looks similar to the Abyss Watchers and Hawkwood. The Shrine Handmaid is Sirris’ Grandmother as hinted at by the Budding Green Blossom. This is further supported by the fact that the Shrine Handmaid doesn't have very nice things to say about this Ash, possibly because she's mad at her husband for leaving her to chase his dreams and join Farron's Legion and also why she wishes to know where you happened upon them and further supported by the fact that Sirris believes you're a kind person after telling the Shrine Handmaid where you found them.
But it's much more likely that these are the remnants of Sirris father, the son of the Shrine Handmaid, who left her daughter in law and her grandchild Sirris to selfishly chase his dreams, becoming a Watchdog of Farron. This theory is supported by the fact that Hodrick, Sirris granddad is a Mound Maker, not a Watchdog and the similarities between his and the mentioned Farron armor are basically non-existent or at least very questionable.
The Ashes appear to be holding the Watchdogs of Farron pendant. Although it's possible that the Ashes are holding the Pendant, a starting gift in Dark Souls I.