Runecarer

Monstermaster or the Runecarer is a human who can summon 7 beasts through rune. No one knows who was first monstermaster, but certainly he was a powerful wizard who succesfuly possesed all beasts to obey the rune on hand. Ordinary people cannot just cut a shape like rune on hand and think that will work. Only a Monstermaster aka Runecarer can draw a rune on someones hand, like they always did, but its mostly applied on babies, because their bodies can adapt on them easily.

In the story
In Runecarer series we know for two living Runecarers and those are: Zeres Ralstone and Leo Brendig. How did they got the runes is still a mystery waiting to be revealed.