Would it be reasonable to assume that one cannot purchase any greater than two levels of this spell from the Wish-Shop - and would require a custom wish to obtain any further levels?
An additional observation:
Nepgear is the first to ascend the coloured elemental to its maximum without the use of Wish-Points.
One must wonder how many Wish-Points have been used to ascend these beings, but I believe no fewer than three have thus far been used in this manner.
Some Angien Fenths that may be useful for testing:
176497, 176513, 176515, 176516, 176524, 176525 - these are all within mine inventory, and are gladly donated to this bug-amending cause.
I do not have the artwork for their original forms. If @Muratus del Mur or another doth possess of these illustrations, then I will be able to restore their appearance.
If this location is chosen, do let me know, so that I may create the clicky as desired.
There is at least one other location which may be of use in this regard. Mayhap, the Weaponsmith's could offer his hut for such a purpose?
I confirm that this bug doth exist. The only method I have found to close the window (without refreshing the portal in question) were to activate the cross in the upper right corner of the portal-interface.