Weaver

Pit of Sacrifice
Return from the prophet's room and clear the central dragonkin before taking Dreamscythe and Weaver. Use the outer wall for the drakes' Wing Flap instead of fighting beside the opening in the floor. Keep both breath cones away from the group and agree which drake dies first.
Weaver
Elite DragonkinWeaver turns the central pit into a positioning hazard when its Wing Flap overlaps the group's handling of Dreamscythe.
Abilities

Wing Flap
Strikes enemies in a cone in front of the caster, knocking them back.
Use the outer wall rather than the edge of the central opening as the tank's knockback stop.

Acid Breath
Leave Weaver's Acid Breath cone clear even while the group is attacking Dreamscythe.
Tank- Secure Weaver as the group returns from Jammal'an. Keep your back to the outer wall and its Acid Breath away from the tank holding Dreamscythe.
Healer- Cover the player holding Weaver even if Dreamscythe is the damage target. Keep a route along the outer floor so following a Wing Flap cannot take you toward the pit.
Damage- Keep Weaver controlled while attacking the called drake. Reposition along the outer floor after Wing Flap instead of crossing the pit or Weaver's frontal cone.