Crackpot theory with Mordekaiser, Sion, and Jarvan
Hear me out. This theory is really simple
Mordekaiser: assume that he fathered some children during his human life. Maybe even it was even a Genghis Khan situation.
Sion and Jarvan are the last of his descendants. The other lines died out. This is why only and only a Jarvan’s blood could be used to resurrect Sion.
Only Mordekaiser and Swain are aware of this.
Use this theory for free Riot ;)