Maybe during shroud, spending void units accrues green units, when you have 4 units, do an extra weaponskill. The extra weapon skill before the communio forces some time in between to use egress out of melee into a safer communio cast since communio is actually a ranged spell. This gives the opportunity to use the enhanced Harpe as well as Harvest Moon. Maybe using communio can enhance Harvest Moon as well. Then tele back to mob to reiterate the cycle.

(Void Reaping -> Cross Reaping -> Lemure Slice)x2 -> New Skill with 4x green orb cost -> egress -> communio -> enhanced Harvest Moon -> enhanced Harpe -> ingress.

This it what my combo looks like already (when their are no damagning AOEs outside melee range) so, I'm biased for a new skill that enhances the ranged end of the combo.