Absolution for All

Make this macro:

/target Fugitive Soul
/run SetRaidTarget("target", 8)

It'll save you a lot of time.

Once you turn in a [npc=160149] to the [npc=169917], you do not have to wait for the ritual to complete neither have to kill the manifestations that spawn to receive credit for the achievement. You can kill them for extra reputation or some loot, but you might as well ignore them whatsoever.

Some good areas to run around below. Do this for a few days and you'll have it, easy.
Souls award 50 rep with The Avowed when turned in so pop on a rep buff if that's a priority for you.
The area around Aurica has lots of Confirmed Dredgers to farm Atonement Crypt Keys for Crypt Kicker.
Once you're done with keys I'd say the best area is near the Archivist.
Not sure about respawn times, seemed pretty inconsistent.

Happy farming, Cryptkeepers!

Graveyard

/way 70.59 52.06 just outside graveyard (east)
/way 70.9 55.26 behind sin stone
/way 71.71 54.42 end of platform
/way 69.23 52.95 in small graveyard
/way 69.63 54.98 behind another big stone
/way 70.28 54.95 behind big stone
/way 69.2 52.98 in a small graveyard
/way 67.57 52.96 just outside graveyard (west)

Near Achivist

/way 75.13 47.16 triple spawn
/way 75.26 51.82 double in this area
/way 71.16 55.04 one more nearby
/way 71.52 53.36 double in the building
/way 72.28 44.36 inside building with the protector

Near Aurica

/way 69.71 45.87 behind little house behind her
/way 70.50 43.32 next to silent proctor
/way 71.15 41.66 hiding around corner
/way 68.94 41.27 jump down from ritualist platform
/way 64.88 43.79 opposite on near side on balcony don't pull executor
/way 65.48 44.37 behind big stone

South West Area

/way 64.94 48.39 in other courtyard
/way 66.06 50.63 opposite courtyard in the bushes
/way 64.94 51.05 in litte courtyard
/way 69.66 46.58 other end of outer ledge
/way 68.59 44.58 one end of outer ledge
/way 68.77 48.35 near stoneborn executor