Let me see if I've got this right.
You're saying that there is a rare marking on the ears of Wilhelm II and Nicholas II (to name 2) that is also on your ears and indicates a common ancestor. You're not claiming to be royal yourself, you're just wondering just who that might be?
Nicholas and Wilhelm are related, although not closely so (Wilhelm would have been a closer relation of Alexei). Pretty much every European Royal is related to some extent, some just closer than others, and some in more ways than others. Trying to establish just who this ancestor might be is an incredibly daunting task.
To make matters more difficult is the mathematic idea that every person of European descent alive today is believed to descend from every person who lived roughly 40 generations ago (in the time of Charlemange) and has living descendants. This is because with ever generation your number of ancestors doubles (you have 2 parents, 4 grandparents, 8 great-grandparents, etc), until such a point where the number of ancestors becomes greater than the population at that time in history. Going back 40 generations to Charlemange and the number of ancestors you should have is 2,000 times that of the population of Earth at that time.
So, this means that mathematically speaking, after a point every ancestor of Wilhelm II's Nicholas II's is also your ancestor. So really, who knows where this trait could have come from.