Yep, the job was about being a grave keeper. In a world with Undead that could be born naturally if the presence of death was high it was necessary for cities to have light formation in their graveyards. Since Bo City wanted cut down on this expense some clever mayor came up with this solution.
The formation still existed but was turned off, instead the city employed four Light Mages to use Brilliant Light: Purify a few times in the graveyard every night.
Thankfully his application was accepted once they confirmed he could release the spell but his remuneration was cut in half since he was not at the second tier and would need more time to finish the job.
Since paying Mo Fan would empty his savings and he still wanted to be a super strong mage as soon as possible he accepted the job, besides this one was innocuous compared to the other ideas he had.
Another benefit was that he would finally.. finally stop being a Trainee Hunter and become a bloody Novice Hunter, the barest minimum that the worst Hunting team in Bo City demanded.
Apparantly in bigger cities Hunting teams would take in Trainees as interns without pay and have them run errands for the team and after some time, if and if they were 'pleased' with the person, then they would take him on as a Novice Hunter, but Bo City was such a backwater that Hunting teams couldn't afford to waste time or energy with free labourers.
God dammit
He who was supposed to become the strongest mage in the world had to settle as a 500 yuan a day Grave keeper.
Lin Feng released the Brilliant Light as much as his Star Dust allowed him and spent the rest of the time cultivating in the graveyard and by the time his job was over he had steeled his mind to execute the crazy plan.