The Lag (The Game Master Book #1) by Andrei Levitsky (epub) [BluA]

Summary:
As a shady blackmarket programmer, Ivan "Attila" is never short of customers. The gaming world of MMORPG always needs his services: all those knights and thieves, vendors and vagabonds, monsters and the undead populating the dangerous forests and castles of Gryad Online.

For Attila, things are looking up: the God's Eye, his latest cheat device, is awaiting its buyer. Now Attila can afford a costly virtual suit for a full immersion online experience. Provided the buyer - a burly half-orc Barbarian nicknamed Beast - sticks to his part of the deal.

But how much does he know about Beast, really? And what evil force is playing with

Gryad, disrupting its flow and locking thousands of players inside the game? Who is messing with the world's gears, summoning the spawn of the Dark from their underground tunnels and lairs? And how can Attila and his reluctant companions stop evil from taking over their new world?