Is there something to these wind elemental lords that makes them more knowledgeable than the Titan Keepers? Did the Titan Keepers just lack the magical power necessary? Was Deathwings connection to the old gods leveraged?
I assumed that it had more to do with those elemental lords working with the Old Gods - so it was more a case of the Old Gods willingly undoing their own work, rather than the elemental lords knowing how to reverse it.
Perhaps a lack of knowledge from the Titan Forged? Took King Mechagon using the titan discs to create the Mechoriginator and Gearmaster Mechazod used a toolbox to revert the curse on Gnomes.
Siamat was working for the Old Gods so they were more than capable of removing their own Curse.
The Titanforged who aren’t Vrykul, Earthen or Giants can remove the Curse of Flesh themselves.
Mechazod was already capable of removing the Curse from Mortals.
The Titan Keepers don’t seem that interested in removing Flesh as Odyn himself had no problem with Fleshy Creatures arising from the Well of Eternity’s creation provided the Titanforged started spewing propaganda.
The titan keepers are little more than sentient machines, their ability to learn and grow is thus limited by their dfesign.
By the time the curse of flesh was spreading, the titan keepers had basically collapsed due to Loken’s betrayal.