Shinryu is a dragon isn't it? Why would Ala Mhigan's worship Shinryu? Its never even been mentioned before in FF14.

Plus if you look of screenshots of that cutscene when the sphere is forming you can clearly see very human looking legs.

I don't think we will fight it either. I think Omega is going to blow it to smithereens and blow a hole through a mountain on the other side of the wall.