Global Summoning: I, the God-Level Archmage

There are so many summoners around the world, why is Liu Xiu the only one called the Grand Mage? Because Liu Xiu has two magical powers that no one knows: summoning friends and causing natural disasters of the undead. I understand calling friends. If you have many friends, you can call many of them to help out during a fight, but why can't others learn to do this in the case of the Undead Natural Disaster? First of all, you don't understand the meaning of 'calling friends'! When you call friends, you can at most call a group of your own friends to help you fight, but Liu Xiu can at least call strong men from half the world! Not to mention the 'disaster of the undead'. His contracted creature is the largest lord and the strongest king in the world of the undead, and has almost unified the entire alien world! Who dares to mess with him? With just one summons, that little skull wearing a *hat called 'Dumb' can bring most of the other world to earth to surround you. This is the 'natural disaster of the undead'! This novel and its characters are purely fictitious. Any similarity is purely coincidental and should not be imitated.