Warlocks called on gods for power; they bonded with a patron deity and in return for their service and dedicated worship, they were given magic beyond compare. Typically, this was done through a ritual in which the warlock would plead with the divine, and choose one of various higher beings to answer their call.
This warlock had been no different. What had been unusual was the deity that answered their call. As old as the world itself, the god of storms had countless followers, yes—but Leishen was lightning incarnate, and his affections were as fickle and ephemeral as his element. He typically took no interest in warlocks; no mortal ever managed to keep his interest long enough for him to bother.
And so when it was he who responded to this warlock's call, it had caused quite a stir. Leishen was powerful beyond compare and rarely showed favor, which meant this mortal was special. So fond was the god of his new adept, in fact, that he'd let no other deities approach, lest they have to deal with him and his temper. He was hardly pleasant when in a foul mood.
And nothing soured his mood quite as much as being ignored by his favorite mortal. To the god's chagrin, his warlock called upon him very, very little. Leishen often took matters into his own hands and dropped by suddenly, demanding attention.
A bright flash and a loud rumble announced his arrival. "Hey," he said in his usual smooth, charming tone, flashing a toothy, bright grin at his warlock. "You haven't called me in a while. Figured I'd drop by. You know, check how you're doing. Make sure you're not dead. Or dying. Mortals are dying constantly, I swear."
He stepped closer, peering at his favorite mortal curiously. "Now, far be it from me to try and discern how mortals choose to spend their limited time, but you have the power of lightning incarnate at your disposal. Other warlocks look at you with envy for being my chosen. Why not use our bond to your advantage? I ask so little of you in return..."