Galluk

Galluk is a minor antagonist in How NOT to Summon a Demon Lord (also known as Isekai Maou to Shoukan Shoujo no Dorei Majutsu).

He's a thin, high-strung, and arrogant human sorcerer (summoner/mage) affiliated with Faltra City's Mage's Association. Galluk has a strong superiority complex, displays clear prejudice against demi-humans (like elves and pantherians), and acts entitled and rude toward others.

He becomes antagonistic toward the protagonist Diablo after being effortlessly defeated/humiliated in an early encounter (including having his level 30 Salamander summon easily dispatched). Driven by revenge, he schemes against Diablo's group, misuses the Mage's Association's name, and gets fired for it. In his bitterness, he later allows himself to become possessed by a Fallen (transforming into Gregore), escalating his role briefly before meeting his end.

Overall, he's portrayed as a petty, racist jerk who serves as an early obstacle and example of Diablo's overwhelming power.