Rowan had been the one who pierced through the skin of Eosah, and with the strength of his dimensional flesh, he had kept the wound open, and so he continued bleeding all over Reality.
Previously, Rowan had believed that this essence was coming from Limbo. However, after learning that this power belonged to Reality, he knew the time for him to exploit it had drastically reduced.
Reality was no longer alive, and so her Importance could not be plundered forever; whatever was lost could no longer be regained. If Rowan used his Essence storehouse as a baseline, compensating for his lower dimensional level and size, while allocating for the essence lost by the plundering of the Primordials, then it would not take a long time before Reality bled out.