Hhaha ok the one on the shield is a shortened form of the Riddle in a carved stone that shoudl be in a hidden chamber in the Sky haven temple or in the high hrotangar ( most probably )
I could either split the shield in a place ( most probably the skyhaven temple ) while the profecy riddle complete in the High hrotangar monastery .... shoudl make sense?
here is the whole riddle ....
--------------- fin Unahzaal Yol
--------------- kotin fin vith jot segol
--------------- tol Los fin Fiik vokun
--------------- Se gein Lot Keizaal vaal
--------------- heim fin Sahrot Zun
--------------- heim voth Sahqon draal
--------------- heim fin Qeth otin zahkrii
--------------- heim zeim zaan otin Krii
--------------- Het Nok fin Revak Keyn
--------------- se jer Kruziik Krein
--------------- Voth fin quet se Sivaas
--------------- tol fin brom okaaz vintaas
--------------- tol fin iiz pindaar
--------------- tol fin od Lumnaar
--------------- ahrk fin Fo Strunmah
--------------- siiv fin Luv se Bormah
--------------- arkh voth fin zun Kogaan
--------------- drun vul wah oblaan
--------------- Fod fin tiid fen kren
--------------- Alok Nol atmora zoorven
--------------- drun Drem wah Taazokaan
--------------- wah atmora tuz arkh spaan
--------------- wah fin brom Sunvaar
--------------- drun fin dovahmaar
I avoided to put the english translation so you can have fun ^^
Ingame I am thnking to put the vocabulary so people can translate it .... I may be more evil and put it into dragon letters lol but in case I may also add a translator npc that you can bring the copy of the profecy to ... to shorten time or you can have fun with the ingame book with the words etc...
to be decided ...
just as hints :
east sun forge means an Akaviri forge where you will be able to forge the dragonsword and eventually other akaviri ancient armors ( blades stuff )
the shadow is intended as an projected image or a similar to ....
On the quest thing ...
Spoiler
The Sheld was used in processions bythe blades , four of them sustained the shield while the champion using the Dragon sword channeled the Souls of the dragons into this artefact , thus the shield works as a soul gem for special dragons ....
the Idea is that Alduin was not defeated , infact you do not absorb his soul and actually you cannot since is made of the same part of Akatosh and so is Divine in nature , altough could be destroyed it's mortal form , his spirit traveled north , to Atmora ....
There an ancient temple lies in an ancient buried under ice and snow city ....
The reason why is Atmora under snow is because of the Tear of Akatosh , it is said that when Akatosh generated his most loved son and then saw how he turned back into evil he cried and his tear fall on Tamriel in the very hearth of Atmora , bringing the whole land to an Ice age ...
the riddle in the secret chamber tells of how to put an end to the eternal return of Alduin .... infact he will regenerate his mortal form in Atmora in the Tear of Akatosh , but will take ages .... so in meanwhile the Dragons are back to Skyrim ... to put a final end to his eternal return the tear must be shuttered ... it will not save Atmora from it's eternal Ice age ... ( or may be could ) but will stop the eternal cycle of Alduin returning...
so the Dovahkiin altough he was able to defeat Alduin in Sovngarde he is not done with him , he only been able to delay him again ....