I summoned a magician.
If you call someone by screaming, you're probably trying to summon them like a magician would. Magicians have to scream their spells out in order for them to work. So you have to scream out their name when you call them if you want to summon someone.
This is a jukugo word that uses the on'yomi readings of the kanji. You should be able to read this on your own.