User blog comment:Miraka/Prediction of Chapter 385: Spirit King vs King of Hades/@comment-24403746-20140517103039/@comment-5303512-20140517222534

I find it hard to say that they would just call each other's titles just by coincidence.

Your points would make sense if Mard Geer would not have called out Celestial Spirit King's name.

Mard Geer only mentioned his name once and I don't think the CSK would bother with Earthland affairs because he was not expecting to be summoned.